The number of people killed in London during 2018 was the highest figure for a decade. But what is life like for a senior detective investigating these crimes?
The Metropolitan Police's Homicide and Serious Crime Command launched more than 130 inquiries in 2018, as well as continuing to investigate dozens of unsolved cases from previous years.
The unit is split into 18 teams, which each take their turn to be "on call" - meaning that if a suspicious death is reported, they have to respond.
Murder Investigation Team 8 (MIT 8) was on 24-hour call for seven days from Tuesday 4 December.
Based in Putney, south-west London, the team consists of 21 detectives, two police constables and four police staff and is led by Det Ch Insp Noel McHugh, one of the Met's most experienced investigators.
He has 13 "live" murder and manslaughter inquiries that he's responsible for, each of them at different stages.
Some cases are being prepared for court, some are already in the trial process, others are long-running investigations with police searching for a breakthrough, and a smaller number are recent homicide inquiries that need intensive work.
From 07:00 GMT, the team is officially "on call" and is assigned one of the Met's specialist HAT (homicide assessment team) cars, specialist police vehicles deployed by homicide teams if there's a report of a suspicious death.
HAT cars are available 24 hours a day, with dedicated officers ready to take them to the scene as quickly as possible. The principal job of the HAT car detective is to secure the scene and assess what's happened. The vehicle is equipped with kit such as police tape, exhibit bags and log books.
The team assembles in the Putney office to review the trial of Rahim Mohammadi, which finished the previous week at the Old Bailey.
Mohammadi had been found guilty of strangling Lea Adri-Soejoko at an allotment in north-west London in February 2017 and sentenced to life with a minimum 19-year term. He throttled the 80-year-old with a mower cable and left her body inside a locked shed.
Detectives, led by Det Ch Insp McHugh, found inconsistencies in Mohammadi's accounts of his movements when they interviewed him as a witness. He was a plot-holder at the allotment and known by others there for his threatening, aggressive and violent behaviour.
Det Ch Insp McHugh describes him as "manipulative, volatile and evil" - but it took a retrial for him to be convicted. Several detectives from MIT 8 spent five weeks in court. "People think once someone has been charged, then it's done," Det Ch Insp McHugh says. "But they do so much work, case building, and then at court things come out."
At 09:00, Det Ch Insp McHugh takes part in a "capacity meeting", to discuss resourcing issues in the Met, before helping one of his "brilliant" detectives prepare for a job interview at another force. She gets it, which is good news for her, but not so good for Det Ch Insp McHugh, who'll have to find a replacement, at a time when detectives are in short supply.
Later, he has discussions about Operation Torksey - the inquiry he's leading into the murder of Marvin Couson, who was shot outside a club at Shoreditch in 2002. Mr Couson was taken to hospital with serious injuries to his heart and other organs. He was left unable to communicate or leave his bed and died from a brain injury in August 2015, aged 39.
According to Det Ch Insp McHugh, Mr Couson was the "entirely innocent victim" of a dispute between organised criminal gangs from London and Birmingham, which he had nothing to do with.
There've been several developments in the inquiry over the years, most recently in September 2017, when detectives questioned a prisoner about the murder. Today, Det Ch Insp McHugh is considering what further action may be needed but remains guarded about what it might be. "I was wrestling with a dilemma on a significant line of investigation," he says.
Later in the afternoon, he manages to make it to a physiotherapy appointment before doing more work from home.
One of the other unsolved cases from 2018 that Det Ch Insp McHugh is responsible for is Operation Plana, the murder of Bulent Kabala, in Cockfosters, north London, in February.
In a "targeted hit", the 41-year-old was shot in the head and chest as he got out of the silver Mercedes he was driving. The suspects were in a stolen blue van with Polish number plates.
Det Ch Insp McHugh compiles a report for the Met's director of intelligence because he wants to offer a reward for information that could help solve the case. The director of intelligence will decide whether to allow it.
There's also another submission to complete - to renew the crime reward in Operation Lessingham, the inquiry into the 2015 murder of Josh Hanson, who was stabbed in the neck in a bar at Eastcote, north-west London. He was 21.
The prime suspect, Shane O'Brien, is still at large. Police believe he was flown out of the UK on a privately chartered plane after Mr Hanson died and is being helped by criminal associates, who are providing him with money, false identities and the means to move across borders.
Since the 30-year-old fled, he has had a large tattoo of an owl on his back, to cover up a previous smaller design. Police in the Czech Republic managed to photograph it when he was arrested for criminal damage there in 2017. He gave a false name and was released, with police only discovering his true identity later. He's now on Interpol's "most wanted" list.
Det Ch Insp McHugh, who's in charge of the inquiry into Mr Hanson's murder, has said O'Brien has an "air about him, a presence he will struggle to conceal" even though he uses aliases and may try to disguise his appearance.
Police have appealed previously for information from aeroplane and helicopter pilots, boat owners and those working in ports, as it's thought O'Brien will have been travelling around. They're also looking for people in nightclubs and boxing gyms as well as expats and any women he may have become involved with to come forward.
At 23:30 Det Ch Insp McHugh gets a text that will end up shaping the work of his team for the next seven days.
It's about a burglary in Barnet. The elderly homeowner is critically ill in hospital. He makes some initial inquiries about the case and ensures the crime scene is being preserved, before snatching a few hours' sleep.
At 06:00 Det Ch Insp McHugh is told that the health of the burglary victim, Maureen Whale, has deteriorated.
Ms Whale had been in the house at the time of the break-in and collapsed while phoning 999.
She dies in hospital.
By 08:30 Det Ch Insp McHugh is in the office, where there's "some debate" about whether the case should be handled by MIT 8 and the possible implications for other murder teams in London. If MIT 8 takes the case, colleagues from elsewhere will have to investigate any other suspicious deaths during the week.
A decision is made at 10:00 that MIT 8 should take the case, which requires passing the HAT car to another team. With four of his detectives involved in a trial and one on a course he has to find officers from elsewhere.
"That was quite a few phone calls to try to borrow people from other teams," he says.
A major incident room for the burglary death is set up in Putney but most of the unit make the 14-mile journey to Colindale Police Station for a handover with local officers who initially handled the case.
At the meeting, his team is briefed on local intelligence about burglaries in the area and what CCTV has been seized.
A police family liaison officer (FLO) is despatched to meet the victim's family, a job Det Ch Insp McHugh would normally do but couldn't because of how far away they live.
FLOs fulfil a vital role in cases where someone has died in suspicious circumstances. As well as providing support to relatives as the case progresses, updating them on progress and explaining the investigative and legal processes, they gather information from them about the victim to help the police inquiry.
FLOs provide a crucial link to the senior investigative officer and in some instances details about the victim's personal life, friends and family set-up have provided clues that have helped solve the case.
At 16:00 there's a Gold Group meeting with the borough commander, Simon Rose, before the team heads to the crime scene, which is near Barnet Hospital. "It was really helpful for me to understand the geography of the scene," Det Ch Insp McHugh says.
He deploys sniffer dogs, works out which routes the burglars might have taken, consults the police crime scene manager about a plan for recovering items for forensic examination, arranges for photographs of the scene, liaises with the exhibits officer and ensures a post-mortem examination is organised.
At the same time, members of the public come up with "bits and bobs" of information about other break-ins. "We've got to be really focused and say, 'What is the link?' Some of the links we've got might disappear away," Det Ch Insp McHugh says.
He finally gets home at 21:30.
By 08:00 Det Ch Insp McHugh is on his way to offices at the Met's Hendon site, where there's an hour-long conference call with everyone involved in the inquiry.
There are now 20 detectives working on the case, plus support staff and forensics experts, each involved with different strands, making it vital that everyone is kept up to speed.
"We got a good grip on where we were," he says.
As well as ensuring that leads are followed up and the inquiry is going in the right direction, his role, as senior investigating officer, is to ensure the team's resources and personnel are utilised in the most effective way.
One of the more mundane issues is transport, given the distances between the incident room in Putney, the borough police headquarters in Colindale and the crime scene in Barnet. Sixteen staff have only three cars between them: "It's a bit of a challenge," Det Ch Insp McHugh says.
He co-ordinates further work, including house-to-house inquiries, and finds out whether CCTV images of the suspects can be enhanced.
It's thought a group of "opportunist thieves" targeted Ms Whale's property, after breaking into three other addresses in the area on the same afternoon.
Together with colleagues from Scotland Yard's Press Bureau, Det Ch Insp McHugh prepares statements for the media and arranges a briefing for broadcasters for the next day.
He's home by 20:30 but spends a couple more hours on calls.
Up at 06:00, Det Ch Insp McHugh decides to change the venue of the press briefing. It was to be held outside Ms Whale's house in Barnet but it's switched to New Scotland Yard, in Westminster - because it's pouring with rain.
"Even the dog didn't want to go out this morning it was raining so heavy," he says.
He arrives at the Yard by 10:30 to be given some terrible news about a former colleague on the murder team, who's been told he has terminal cancer.
Det Ch Insp McHugh is clearly shaken as he does interviews with reporters in which he appeals for information about jewellery stolen by the burglary gang.
The media briefing contains some details he doesn't want publicised. His focus is on getting information into the public domain that will trigger a memory or even prick someone's conscience.
The appeal "gets a conversation going" and generates a "positive response", he says. As a result, several witnesses are traced and various names put forward as possible suspects.
At 13:00, Det Ch Insp McHugh leaves for the Old Bailey to meet the family of Mohamed Aadam Mohamed, a 20-year-old stabbed to death in the back with a 12in carving knife after a confrontation in the street in Camden, north London, in September 2017.
The attack was witnessed by Sgt Matthew Ebbs, who was working in plain clothes targeting drug dealers. He confronted the knifeman, who ran at the officer before fleeing, throwing his weapon away on to railway tracks.
Sgt Ebbs arrested the suspect after he tripped and fell and managed to detain him with the help of a cyclist.
Det Ch Insp McHugh's team are investigating the murder and the trial is at a delicate stage, so Mr Mohamed's family need as much support as they can get.
He says Mr Mohamed was a much loved son whose death had left his "dignified and supportive" relatives "devastated". His brother had been fatally stabbed earlier that year, though the details of what happened can't be reported for legal reasons.
"They are a remarkable family who have lost two sons to knife crime in six months and a cousin five years ago," Det Ch Insp McHugh says. He'd had to cancel the meeting with Mr Mohamed's relatives two days earlier because of the Barnet case. "I felt awful," he says.
Ten days later, the trial is over. Erick Ekam, 19, is found guilty of Mr Mohamed's murder and sentenced to life, with a minimum of 17 years. Det Ch Insp McHugh describes Ekam as a "wicked, dangerous" man but praises Sgt Ebbs and the cyclist (who receive commendations for bravery).
"Some knife carriers rely on a street culture of 'no snitching', trying to dissuade witnesses from speaking out," he says. "Here, we have amazing members of the public whose commendable actions have been critical to obtaining this conviction.
"For witnesses in other investigations who are wavering on whether to speak to the police, just look at the difference you could make to a family and our community. It is truly life changing. Do not listen to the rhetoric of the gangs."
Det Ch Insp McHugh works from home - he has to make sure his team are dealing with the growing amount of CCTV material that's been collected in the Maureen Whale case and that items seized from the scene have been sent for analysis.
The results of the post-mortem examination, on Friday, are studied closely. It gives the cause of Ms Whale's death as coronary heart disease - she had not been assaulted. Police later say her death was brought on by the stress of the break-in.
Det Ch Insp McHugh continues to make calls throughout the day, as detectives carry out more house-to-house inquiries. The weekend is a "brilliant opportunity" to do that, he says, as people who aren't at home during weekdays are back.
He writes up a decision log of the investigation. It's a vital record of the key decisions made by the senior investigative officer in a major and complex inquiry - as well as the reasons for the action taken. The log provides an audit trail that can be followed if the case is reviewed or if new material comes to light.
Senior investigating officers are arguably the most accountable officers in the police service. The inquiry pivots around them and every decision they take - from setting the investigative strategy to managing the crime scene, from liaising with their managers to dealing with the press - is "their call" and open to scrutiny.
Det Ch Insp McHugh travels to the police incident room at his office in Putney to co-ordinate work on the Barnet inquiry. He asks colleagues for more detail and analysis of burglaries in the borough as detectives try to find possible links to the break-in at Ms Whale's house.
Work is intensifying to find two people who were spotted locally and who looked similar to the suspects. A lot of officers are involved in tracking the pair down and it becomes "a mini-inquiry" within the investigation. It takes a further 48 hours before detectives are satisfied they're not linked to the case.
Police are also focusing their efforts on the local Iceland store where Ms Whale used to do her shopping. They're scouring CCTV for an image of her handbag, which was stolen in the break-in and is still missing.
They eventually find a photo of it - and match it to a black, leather-like handbag, which is discovered the following Thursday, stuffed in a hedge half a mile from Ms Whale's home.
Could this be the breakthrough detectives are waiting for? The bag is sent for forensic analysis.
Det Ch Insp McHugh chairs an office meeting. It's a "great opportunity to piece the jigsaw together" in the inquiry, he says. His main focus is preparing for another public appeal about the Barnet burglary. The suspects have yet to be identified or arrested.
Sometimes, when there's a lot competing news, one of the difficulties for detectives is maintaining media coverage of a case. Fresh snippets about the crime, photographs and quotes from relatives can help to keep it in the public eye and boost the chance of getting information.
At the same time, some details may be held back, either because they're too sensitive or to give detectives an advantage when they come to question a suspect.
Det Ch Insp McHugh finalises the text of a press release about Ms Whale's death, which declares police are officially treating it as a case of "manslaughter".
He puts together a statement from Ms Whale's nephew, Lawrence, and her niece, Gina. "It is heartbreaking that our Aunt Maureen is no longer with us - this last week has felt like a nightmare," they say. "This must have been a truly terrifying ordeal for her. All we think about now is of how vulnerable and scared she must have felt.
"She was a private, independent woman who was extremely proud and didn't deserve to die in this way. We urge people to come forward. The police need the names of those responsible."
Det Ch Insp McHugh and his team are officially off-call at 07:00. It's meant to be their rest day but it's cancelled because they're out in the Barnet area publicising their appeal. "We've never had that Tuesday off in all the time that's been there - because we keep getting investigations," he says.
He says during the inquiry into the murder of Mohamed Aadam Mohamed some of his team didn't have a day off for 20 days. They apparently slept on the floor of the office, he says - along with the mice.
All in a week's work for a murder detective.
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