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Today's #TuesdayTip is another book review. This time it's the brilliant "The Real CSI. A Forensic Handbook For Crime Writers", by Kate Bendelow.
Bendelow has the unusual distinction of not only being a currently serving forensic scientist with Greater Manchester Police, but she is also the author of two novels featuring CSI Maya Barton. Because of this, the handbook is very much geared towards writers.

I was really impressed with this book. Although it has been around for a few years (2017), it's still going to be pretty much up-to-date for a few more years yet, and of course a lot of things don't change. These sort of books tend to fall into two categories - what I call 'dippy books', where you dip into or out of them using the extensive index to find the specific topic you want to read about, and 'cover to cover' books, where you sit down with a cuppa and read from the beginning to the end.

Unusually this book is both. The first chapter, 'A day in the life of a real CSI' is a chapter to be read in one sitting. As are the next couple, 'Dealing with death' and 'Crime scene preservation'. After then, the book is divided into more broad chapters with lots of subsections, such as Fingerprints, DNA, Footwear, Trace evidence, Fire scenes, Drugs and toxicology, and Firearms. You can either read the whole chapter, or home in on a subsection, such as "issues affecting fingerprint quality".

​The science is well written and detailed and aimed broadly at a general audience. Those who haven't studied science since they were at school may find themselves Googling the odd term that they aren't familiar with or accessing the glossary at the end, but generally speaking it's pretty accessible.
Another advantage that this book has over some in the field, is that Bendelow is still working as a CSI, rather than looking back on a career or observing from afar. This is real boots-on-the-ground stuff and helps dispel the myths as portrayed on TV or in fiction. Obviously, as writers we are more concerned with telling a story than 100% accuracy, but it's always best to learn what the rules are before you decide to break them.

One of the things I like about this book is that the writing is very personable, with plenty of examples of true life cases. Both infamous tales that you may have heard of, and those that Bendelow has encountered personally in her day job. What demonstrates that Bendelow is herself a writer, is that almost every section ends with thoughts about how a writer could use what she has just described or things to be careful of.

Overall, I was very impressed and very much recommend it to both writers and those who just want to know a bit more. And to quote the wonderful Lynda La Plante 'Every crime writer should have a copy of this book on their desk.' Who am I to disagree?

If you are a writer with a tip to share, or fancy writing a fictional interview between you and one of your characters, please feel free to email me.

Until next time,
All the best,
Paul

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Welcome back, and a Happy New Year! This week's #TuesdayTip is a review of a fantastic book I received for Christmas.
Murder Investigation Team - How Killers Are Really Caught - is a brilliant account from recently retired Scotland Yard detective inspector Steven Keogh.
Released in 2022 (and containing data up to March 31st 2020 when things changed somewhat!), this is an in-depth insight into the process of solving murders and taking them to trial.
Although it deals specifically with the Metropolitan (London) Police Service, who divide Greater London into autonomous Murder Investigation Teams (MITs) and thus might be operationally slightly different to the way other police forces deal with such crimes, most of it is generally applicable to other forces in England and Wales.


Unlike some books, which are more like reference guides designed to be dipped into and out of, this can be read cover to cover (which I did over three days). I was really impressed with it, and heartily recommend it to authors writing British Police Procedurals, and non-writers who want to learn more about what really goes on. Keogh's writing style is both personal and personable and very accessible, without feeling patronising for those with previous knowledge. It feels almost as if he has been invited to give a lengthy talk to a room full of interested laypeople. And I mean that as a compliment and endorsement.

Divided into chapters, he first takes us through some of the technicalities of what is murder, how it differs from manslaughter and some of the potential defences or partial defences (ie when you would push for a murder prosecution, when you might decide no offence has been committed, and why a person might be convicted of manslaughter, rather than murder). He also describes the structure of an MIT (it might be subtly different in other forces) and the roles of individuals.

The remainder of the book is broadly chronological, dealing first with the crime scene(s). This includes forensics and what they are specifically looking for. Of particular note is the section on phone data. Keogh is fascinated by this and voluntarily took on this role in many investigations, so he has real expertise.
The next chapter is the longest and concerns the investigation itself, but is sub-divided. He looks at investigative thinking, lines of investigation and the arrest and interview of suspects. In this subsection, he describes how modern interviews are conducted. There is then a section where he answers some of the questions that people regularly ask.
Finally, there is a chapter describing a trial and the aftermath.

Throughout the book, he illustrates his points with anonymised case files. As a mark of respect, he doesn't name any victims or suspects, although afficionados of true crime will probably recognise some of the more well-publicised cases. He also has regular "Myth Busters" and "Did You Know?" facts. All crime fiction writers accept that the relating of an investigation in exacting detail would be rather less exciting than they hope for, but I'm a firm believer in the adage that to break the rules, you need to know the rules first. Knowing how your book needs to differ from real life for dramatic purposes can help you choose what liberties to take, whilst minimising the gnashing of teeth (and smart-arse Amazon reviews) of the armchair detective.

The book is refreshingly honest. Keogh is not afraid to admit to mistakes that he and his team have made, and the learning that came from them, and whilst the book is understandably very pro-police, he admits to failings. He is also quite happy to point the finger where necessary at the impact of government cuts, the sometimes cut-throat and often underhand or callous tactics of defence barristers, and the sometimes inexplicable decisions made by juries. Throughout it, he is clearly in awe of the dignity shown by victims' loved-ones.

My wife, who is not a writer, commented that she is looking forward to reading it next because it looks really interesting. I think she'll thoroughly enjoy it, and so will you.

Steven Keogh runs The Murder Academy website that looks at True Crime and the solving of crimes.

For today's #TuesdayTip, I have chosen to review a TV documentary series that I highly recommend for those seeking an authentic insight into UK policing.
If true crime is what you are after for your TV viewing, there is no shortage of programmes to choose from. There are whole channels that are devoted to it. But the quality varies enormously, from the down-right sensationalist to the truly insightful. Unfortunately, you can't always be certain what you are tuning into. Some of the US series in particular are quite bad.
Furthermore, police procedure varies enormously between the US and the UK, so if you are looking to write a UK police procedural they are of limited use. That's not to say they should be dismissed out of hand; I've certainly found inspiration for plot ideas over the years.
However, if you want an authentic UK-based series (specifically England and Wales - Scotland and Northern Ireland have slightly different justice systems), I heartily recommend 24 Hours In Police Custody. Aired on Channel 4 in the UK, many (but strangely not all) programmes are archived on the free All 4 streaming service.

The name of the show is something of a misnomer, and is why I was rather late to the party, only finding it during lockdown. It conjures up images of fly-on-wall scenes from cameras above the custody desk as an endless parade of drunken idiots are booked into the cells for the night - think Big Brother, but everyone is wearing a grey tracksuit. However it is far from that.
Based primarily in Luton, it follows detectives from Bedfordshire police as they solve serious crimes. Camera crews follow them from the initial 999 call right through the investigative process, including interviews with witnesses and suspects, candid discussions with the detectives and specialists involved, and occasionally victims' loved-ones. Forensic specialists are shown going about their business and if necessary, the science explained. Sometimes body-worn camera footage is also shown. My wife and I sometimes joke that you can guess who is guilty, as they are the only person who hasn't had their face pixelated for legal reasons!
An individual episode might span several years, with the programme only aired once all the legal proceedings are completed (and the outcomes are given before the end credits). There are a couple of special episodes that pick-up detectives revisiting a cold case many years after the original crime was committed.

As a writer of police procedurals, I have found it invaluable. The interview scenes are especially useful. Conducted by trained interview specialists, the days of banging the table and trying to intimidate the suspect into a confession are long gone. In fact, most interviews are 'no comment'. However, there is a real science to effective interviewing, plus a raft of legislation that has to be adhered to.
Equally insightful is the CID office and the team briefings. This is where you get a real sense of the scale of a major murder investigation. As writers, we tend to keep our cast of characters limited, so that readers don't get confused with too many names, and all characters get a chance to shine. In reality there are dozens of police officers and civilian specialists, each of whom plays their part. You should aim to reflect this in your books, without swamping the story with detail and too many featured characters.
It also captures the sheer banality of most murders. Generally speaking, the victims knew each other, and it's less about working out who the suspects are than figuring out what role they played in what transpired. Yet it is still a fascinating watch. Occasionally the investigations are more of a whodunnit, especially some of the special episodes that might have several parts.

If you want your writing to be realistic, you would do well to watch a few episodes of this excellent show.
Do you have any recommendations for useful documentaries? Feel free to comment here or on social media.
Are you a writer with a tip to share? Don't be shy, I'm always looking for guest bloggers or ideas for future posts.

I am going on a brief hiatus for the holiday period. I'll be back in the new year. Until then, happy holidays!
Paul 

​In today's #TuesdayTip I am going to highlight a huge difference between crime writers and real-life police officers.
Writers love custody clocks!
In most jurisdictions around the world, there are strict limits on how long a suspect can be detained for questioning before they have to be charged with a crime or released. This is sometimes known as 'The Custody Clock'.
This article will focus on the UK, specifically England & Wales, so if you are setting your book somewhere different, be sure to do your research. Similarly, the rules have evolved over the years, so again make sure of the facts for your time period.

For law enforcement, these limits can be something of a headache. The clock essentially starts from the moment of arrest, meaning that unless the police want to release their suspect (either without charge, or on bail, or more recently 'under investigation'), they have to amass enough evidence within that time to pass the 'threshold test' and receive authorisation to charge from the Crown Prosecution Service (or Procurator Fiscal in Scotland).
But for a crime writer, this same restriction injects a element of dramatic tension into the narrative - will your hard-working detectives manage to reach the threshold in time, or will a suspected serial killer be let back onto the street, to potentially kill again?

PACE yourself - the rules in England & Wales.
Rules concerning detention limits are governed by the Police And Criminal Evidence Act of 1984 (specifically Code C).
When a suspect is brought into the station for questioning under caution, their detention has to be authorised by a custody officer - this is usually a trained constable or sergeant. They are responsible for the welfare of the detainee (not the 'prisoner' or the 'criminal') when they are in custody, and are independent of the investigation. The custody officer has to be satisfied that that they have been correctly arrested, they have been properly cautioned, and there is reasonable suspicion that they may have committed an 'indictable offence'.
At this point, they will be risk and medically assessed and a solicitor arranged if requested (a 'duty' solicitor will be engaged for free, if they cannot arrange their own representation). Translation services will also be organised and, if necessary, an appropriate adult (for example if the detainee is a minor or a vulnerable adult).
Contrary to what is shown on TV, their phone call can be withheld if there is a a risk that they may use it to communicate to accomplices.
This is the point at which they may be searched and fingerprints and DNA etc taken.  
If you want to see this in action, I recommend fly-on-wall documentaries such as 24 Hours In Custody.
Unless you are specifically intending to write about police corruption, avoid the temptation to 'bend the rules'. Neither the custody officer or the detainee's solicitor will let this happen. I recommend making a note of what time your character is arrested in the timeline of your book and when they would need to be released to avoid any errors.

Period of initial detention.
Persons can be detained without charge for an initial period of up to 24 hours after their arrest. This time starts typically when they are presented at an appropriate police station and their detention is authorised - this is referred to as the 'relevant time'.  No later than 6 hours after this, their detention must be reviewed by an inspector or above, followed by further reviews every 9 hours. The review officer has to be satisfied that there are still reasonable grounds for them to remain in custody. This cycle of reviews is sometimes referred to as the 'review clock'.  
This is often overlooked by writers of fiction, but could be a source of narrative tension.
Initial extension.
An officer of at least the rank of superintendent, who isn't directly involved in the investigation, can review the detention and extend it by up to 12 hours, to a maximum of 36 hours from the relevant time. Further 9 hour reviews by an inspector are still required. Again, they have to be satisfied that there are reasonable grounds for their continued custody.
Further extensions.
Further extensions can only be granted by a warrant issued by a magistrates' court. These can be up to 36 hours in duration to a maximum of 96 hours (There can be multiple extensions of 36 hours or fewer, it is just that the total time must not exceed 96 hours from the relevant time). For practical reasons, these applications can be made before the previous extension has elapsed or up to 6 hours after.
Disposal or charge.
Once the relevant extension has expired, the detained person has to be either released (disposed of) or charged - remember, in serious cases, charging must be authorised by the CPS or Procurator Fiscal.
Upon charging, the suspect will be taken to a Magistrates' Court (the 'lower' of the two UK courts - no jury). 
For a lesser offence (less than six months maximum custody or fine) the case may be heard and dealt with there and then. For serious offences that are beyond the remit of the magistrate to deal with, the magistrate will then commit them to a jury trial at the Crown Court. They do not enter a plea at this point. The detainee can either be placed on 'remand' (sent to prison) to await their trial or released on bail to return at a later date. Unlike in the US, there is no 'bail bond' - in other words, you cannot stump up money to avoid being remanded. The decision to remand into custody is based on flight risk and potential danger to the public. Any time served on remand will be subtracted from any subsequent custodial sentence, so people convicted can in theory be found guilty then released immediately due to time served.

If there is insufficient evidence for them to be charged at that time, then the police have several options.
No Further Action (NFA).
There is insufficient evidence that the offence occurred, or no realistic chance of a conviction. They are released, but this decision can be revisited if further evidence comes to light. They are still recorded as having been arrested.
They can be released on pre-charge (police) bail pending further enquiries.
Bail can have a wide-range of conditions imposed. For example, no conditions set, the requirement to report to a police station at regular intervals, surrendering of passports, restrictions on movements, electronic tagging or who they associate with etc. This would be authorised by an Inspector or above.
The suspect is required to surrender to the police for further questioning etc when asked to do so. Breaking these rules can result in them being remanded in custody. Unlike the US, the requirement for a surety (financial or otherwise) is extremely rare. As a writer, I'd recommend not going there.
Note: The rules surrounding bail changed in April 2017 in England & Wales.
Prior to this, people could and would be placed on bail for months, even years, as the investigation ground on. Given the impact that bail restrictions can place on a person's life (not to mention the complications and stigma arising from being suspected of a crime - eg suspension from work, or the blocking of child access arrangements, not to mention the stress and affect on relationships), it was decided that it should be restricted to a period of 28 days. An extension of 3 months can be granted by a senior officer (superintendent or above), after which applications need to be made to a magistrates court  (the complexity of Fraud cases mean that these can have longer time limits). 
Fundamentally, the change was to stop police dragging their heels and keeping potential suspects on bail 'just in case'. Remember, in the eyes of the law, these people are innocent.
Once this period of bail has expired they must either be charged or disposed of. 

To compensate for the fact that in complex cases it may take longer to amass the necessary evidence to charge than the bail rules allow, a new option was created.
Released Under Investigation (RUI).
This differs from bail in that there can be no restrictions placed on them, and they do not have to keep police informed of their whereabouts. They will need to return for further questioning if asked to do so and the police can retain their property. 
Note: being 'de-arrested'.
This is different to being released without charge. It can happen for example in cases of mistaken identity or if a person is able to give a good reason for their actions (eg arrested at the scene of a crime, but they later demonstrate that they had just arrived there by coincidence). The fact of their arrest is not logged, but may be recorded in the police report if relevant and in theory can come up on an enhanced DBS check (a criminal records check that determines if a person should be barred from certain types of work).
The timing here is crucial - the de-arrest should happen before the detainee is processed by the custody officer.

Additional rules, complications and exceptions.
In order to stop police 'gaming the system', the custody clock and the review clock are not reset each time a person is released from custody. So police cannot simply release a suspect approaching their detention limit, then detain them again and have another 24 hours.
In simple terms, if a person is detained at midday on Tuesday, reviewed at 6 pm and released from custody after 10 hours, then if they are brought in again for further questioning on the Friday, the police only have 14 hours remaining of their initial detention, before they need to extend, charge or release. They will also need a review within 5 hours (9 hours, minus the 4 hours they were in custody after their first 6 hour review). 
A change to PACE in 2006 allowed people suspected of terrorism offences to be held without charge for up to 28 days. The rules are outlined in the Terrorism Act 2006.
Detainees are entitled to 8 hours sleep every 24 hours, 3 meals and drinks 'on demand'.
The custody officer will enforce these, so no getting your naughty detectives to interview them for 48 hours straight until they break!
The custody clock does not stop during this time.
Suspects are not typically questioned under caution in hospital or outside a police station. But exceptions to the rules do exist and are outlined in PACE Code C.
Forensic delays don't give you a free pass.
It can takes days or weeks to fully search a property or process samples. Unfortunately (for the police), they can't simply hold onto a suspect whilst they await what may or may not turn up. The detention limits are inviolable. Unless they have other evidence sufficient for them to be charged, they have to be released.
Running down the clock.
If a suspect believes that the detectives don't have enough to charge them within the custody time limits, then they may try to 'run down the clock'.  By refusing to comment or cooperate they may gamble that the investigating officers may eventually have to release them without charge.

I stated at the beginning that I love custody clocks. Although the time limits can sometimes cause logistical problems when structuring a novel (eg can I realistically get a DNA match back before the time expires?), the narrative opportunities from the race against time are well worth it. Can the interviewer get the suspect to stop 'no commenting' and cooperate before they run the custody clock down?

Where do you stand on custody clocks? Are they an annoyance that get in the way of your story, or are they an opportunity to be exploited?
As always, feel free to comment here or on social media.
Until next time,
Paul.

Welcome to this week's #TuesdayTip.
​Today is all about writing about UK police.
I'd planned on doing something along these lines for months, but recently I have been hanging around some writers' forums and I've realised that writing about the police, especially if you've never written a crime novel before, can be very intimidating. Furthermore, if you aren't a resident of these fair isles, then getting those little details that make a book set in the UK feel 'authentic' can be really difficult.
This is an unapologetically long post, so feel free to skim.
First of all, full disclosure. I have never been a police officer, and there are many who are far more qualified than I to answer specific questions about procedure etc. But I am a lifelong UK resident, and I have written more than ten police procedurals that - touch wood - readers seem happy have got it mostly correct.
If you're looking for specific details, you can do far worse than to check out Graham Bartlett's blog.
Basically, this is a bluffer's guide for crimewriters. Any errors are mine. If you spot one don't be shy about letting me know!
About this article.
First, I am going to assume that you are writing modern police procedure (ie set within the last 10 years or so). Second, that you are setting your book primarily on the UK mainland, not an overseas territory, and your officers work for a territorial force, not a specialist force such as the Ministry of Defence Police, the British Transport Police or the Civil Nuclear Constabulary. Third, my books are all set in England, so everything is based on English and Welsh law. Both Scotland and Northern Ireland have their own legal systems. Whilst a sworn police officer from one UK jurisdiction can exercise broadly the same powers in any of the other two jurisdictions (subject to certain rules being met), terminology and rules vary, so I urge you to double-check the details if you are setting your story outside England and Wales. A Scottish reader will not be impressed if you talk about the Crown Prosecution Service, rather than the Procurator Fiscal in a book set in Edinburgh!
The Basics.
The UK has 45 territorial police forces.

• 43 in England and Wales, based geographically.
• Police Scotland (consolidated from 8 regional forces to one single organisation in 2013).
• The Police Service of Northern Ireland (PSNI). This was known as the RUC (Royal Ulster Constabulary) until 2001, when it was rebranded in an effort to make it more inclusive, particularly to members of the nationalist communities.

Policing in England and Wales is overseen by the Home Office which is headed by the Home Secretary. The Ministry of Justice is responsible for courts etc. MI5 and MI6 are the domestic and overseas intelligence services respectively, and as such are not considered police.
A key difference between the UK and many other countries is that the police service is very joined up. This contrasts with the States, where a region can be policed by a city police department, the state police and even the local sheriff's department, all of whom have different responsibilities and organisational structures etc. For convenience's sake, you can generally regard the UK police service as a single organisation, with regional branches.
All forces use the same major computer systems. For example the Police National Computer (PNC) and the Home Office Large Major Enquiry System (HOLMES2). All vehicles are registered at the DVLA in Swansea, Wales. Therefore UK police are not plagued by the issues suffered by some countries, where an offender can mask their criminal history by simply committing crimes in different parts of the country. Details of an offence recorded in Devon and Cornwall for example, are immediately available to colleagues in Newcastle, should they have reason to look up that individual on the PNC. For major enquiries, such as murders, details previously inputted into HOLMES2 in Manchester about one crime, may be drawn to the attention of officers in London investigating a similar crime (the system has a form of Artificial Intelligence that allows it to recognise patterns and suggest courses of action).
Addressing misconceptions.

• We do not have an FBI.

The United States needs a federal law enforcement agency that can act across multiple states and jurisdictions. For the reasons listed above, the UK doesn't really need one. The National Crime Agency (NCA), is sometimes referred to as the UK's version of the FBI, but it isn't. It specialises in organised crime, rather than the FBI's broader remit.

• "New Scotland Yard" or "The Met" are colloquial terms for London's Metropolitan Police Force.

Although the biggest force in the UK, they are not like the FBI. Other forces are typically quite capable of dealing with most crimes, and the Met will not swoop in uninvited to take over. A smaller force might request assistance if they feel that the Met has additional resources or skills that would be useful. In Golden Age detective novels (think Agatha Christie's era) small, rural forces might never have dealt with a murder and so they might 'send for Scotland Yard', but that is no longer the case in modern times.

• All UK police officers are constables.

Regardless of rank and title, whether they are on the beat or behind a desk, they remain a sworn constable with the same powers of arrest etc.

• UK Officers carry Warrant Cards, not badges.
• Suspects are charged by the Crown Prosecution Service (CPS).

The CPS (Procurator Fiscal in Scotland and Public Prosecution Service for Northern Ireland) authorises charging of suspects for serious crimes. The closest analogy in the US would be the District Attorney. The CPS will work with officers to determine if they have reached the 'threshold' for charging and then conduct the prosecution. CPS Direct allows for charging decisions to be made electronically or by phone 24/7.

• UK suspects are entitled to a solicitor not a lawyer.

It's a small detail, and is essentially just a label, but lawyer is a rarely used term in professional circles (although the public will often refer to them that way). In the UK suspects have solicitors, and are represented at trial by barristers.

• Suspects are entitled to free legal counsel if they cannot afford their own.

Police stations have lists of independent 'duty solicitors' who can provide this. Unlike the US, where detectives will try and stall suspects from 'lawyering up' as long as possible, in the UK suspects will typically request one as soon as they can. I am assured by defence solicitors that it is not unknown for an interviewing officer to try and push a suspect to get a solicitor - ultimately, it is better for everyone concerned if it is all above board. The 'no comment interview' is as popular in the UK as the US!

• Custody Officers are responsible for a detainee's welfare.

When a person is arrested, they are taken to a police station for detention or questioning. The custody officer (usually a sergeant) authorises their detention (books them in) according to strict criteria. They are then responsible for their wellbeing - physical, mental and legal. They take this role seriously, and cannot be compelled to bend the strict rules surrounding time limits or access to legal counsel by a senior officer. Unless your book specifically has a corrupt or negligent custody officer as part of your story, don't try and fudge this.

• The rules for arresting or cautioning suspects, detaining them, conducting searches and interviews etc are the same across the entire country.

In England and Wales this is governed by the Police and Criminal Evidence Act of 1984 (PACE). Scotland and NI have broadly similar documents. I am going to write a specific blog post on this, but it is worth downloading a copy as reference. Unless your officers are bent, they will adhere to this. Wikipedia is a good introductory source.

• The term WPC (Woman Police Constable) fell out of use years ago.

No distinction is made between male, female or non-gendered officers.

• The correct term is 'senior officer' not 'superior officer'.
• Detective is not a title or mode of address.

Officers would be addressed by their rank or name, not as 'Detective Jones'.

• Detectives do not outrank non-detectives (see below for more detail).
• UK Police Officers are not routinely armed (see below for more detail).

UK Police Ranks
With the exception of the most senior ranks, which can vary slightly between forces (eg the head of the Metropolitan Police is called 'Commissioner', rather than Chief Constable), UK police forces use the same rank structure.
(Note that the abbreviations in brackets can vary, so are only a guide to some of the more common ones).

• Constable (PC or Con)
• Sergeant (PS or Sgt)
• Inspector (Insp)
• Chief Inspector (Ch Insp)
• Superintendent (Sup)
• Chief Superintendent (Ch Sup)

Then there are the chief police officers, who are largely managerial.
Assistant Chief Constables (ACC)
Deputy Chief Constables
With the head of the force referred to as the Chief Constable.

All these officers typically wear uniforms, and are often referred to collectively as 'uniformed officers' to distinguish them from plain-clothed detectives.

Officers who undergo additional training and pass appropriate exams to join the Criminal Investigation Department (CID) have the prefix 'Detective' added to their rank, however it is not a rank in and of itself. They typically wear smart business attire or clothing appropriate to their role.

• Detective Constable (DC Det Con)
• Detective Sergeant (DS)
• Detective Inspector (DI or Det Insp)
• Detective Chief Inspector (DCI or Det Ch Insp)
• Detective Superintendent (DSI or Det Sup - there can be some variation here)
• Detective Chef Superintendent (DCS Det Ch Sup)

The prefix is not used for chief police officers, who typically have a wider managerial role than just investigation.

It is important to stress that Criminal Investigation is a specialism, not a promotion. A detective constable does not outrank a regular constable. A constable joining CID won't be promoted to DS. A sergeant joining would not have to start again from the rank of DC.
Not everyone guns for promotion. Many officers happily remain as constables or sergeants for the entirety of their career, having found a role that suits them. Many become extremely specialised and are respected for their skills, rather than their rank.

Firearms.
This is probably the thing that most confuses non-UK citizens.
(Note: Because of the Troubles, the rules in Northern Ireland are different.)
Rank and file police officers are not armed and are not trained in firearm use. Gun crime is very rare in the UK and the private ownership of handguns is illegal. Other types of firearms are strictly licensed.
Armed officers are referred to as Specialist Firearms Officers (SFOs) and have to undergo specialist training. The guns are issued as needed, under strict authorisation. They are returned after use and officers are subject to the same laws as any other citizen, so they certainly do not take them home, nor do they have a personal weapon.
Only SFOs can use guns - regular officers cannot simply go and get tooled up, no matter the situation (decades ago, this was not the case, especially after the war when many officers may have done military service, which is why older crime fiction might have officers pulling a gun).
SFOs called to an incident will be in Armed Response Vehicles (with the guns secured in the boot of the car - not the trunk, that's an American term).
Armed patrols do exist of course. For example at ports or even on the streets during heightened terrorist activities, but again these will always be trained officers. Special Branch is a division of the Met and will provide armed protection for VIPs.
TASERS are similarly restricted.
A typical uniformed police officer is issued with a metal extending baton (ASP), the modern replacement for the old wooden truncheons, and incapacitant spray. It might not be as glamorous as a Glock, but I'm reliably informed it gets the job done!

Modes of address/nicknames.
Although the UK is a rather informal society, the police is still a hierarchical structure.
Senior officers would refer to junior officers by rank (eg constable) or by their name (or nickname).
More junior officers would refer to senior colleagues by rank or titles such as Sir, Ma'am or more informally Guv (abbr of Guvnor), Boss, Chief, Super (Superintendent) etc. This will vary regionally and within groups. As in any organisation, friendships develop and in more informal settings long-standing colleagues may refer to senior officers by their given names or nicknames.
The police are often referred to by the public as Coppers or Bobbies (after Robert Peel, father of the modern police service - the related term Peelers is rarely used these days). Regional terms might include Bizzies (for example on Merseyside), as well as less polite terms such as Pigs. American terms such as Fuzz or even 5-0 or Feds are occasionally used, although usually by younger people.

Well, I think that's about it!
As I stated at the outset, this is a bluffer's guide for crimewriters and is not comprehensive.
If you spot anything that is missing - or any errors! - please don't hesitate to let me know, and I am open to editing the post.
I hope it is helpful.
Until next time,
Paul