IT WAS the brutal attack on a 17-year-girl that shocked Portsmouth.
In the early evening of April 11 this year, James Hemming dealt blows with a 16oz claw hammer that left the teenager with severe head injuries.
Detectives at the time feared she may not survive and were soon engaged in a major manhunt following the 999 call at 6.58pm.
Today as 29-year-old Hemming, of Cross Street, Portsea, is jailed for 12 years, the lead investigator lifts the lid on how he was brought to justice.
Speaking exclusively to The News, Detective Chief Inspector Liz Williams told how the investigation led from a single grainy image, then to an e-fit and ultimately ended with Hemming behind bars.
Initially all investigators had to go on was a blurry CCTV image of the suspect leaving Shearer Road.
What we had here was a picture without a name... chasing a picture for a couple of weeks is very intenseDetective Chief Inspector Liz Williams
They soon started to scour footage, working out the route he took to flee the scene.
Huge numbers of resources were drafted in as detectives watched 1,000 hours of seized CCTV footage from 250 different cameras.
Specialist officers from the Metropolitan Police Service’s unique super-recognisers unit were drafted in to view the CCTV in a bid to locate the unknown attacker.
The unit has built up a reputation for spotting some of London’s most prolific criminals in the capital’s crowded streets.
And in Operation Gather they were drafted in alongside Hampshire’s police’s Major Crime Investigation Team to find Hemming.
They followed the CCTV, connecting fragments together, moving from one camera to the next.
At the time, Hemming was just an unknown figure to police.
Officers had also turned to the public to help – with one image of him released publicly on April 13 and another from Barclays Bank CCTV released on April 17.
Crucially, he was a figure without a name.
Phone records connected a pay-as-you-go phone to the victim’s phone.
CCTV from the O2 shop began to build up a picture of where Hemming had been when he got the top-up for the phone.
This left police – as Det Chief Insp Williams says – ‘chasing a picture’.
Det Chief Insp Williams adds: ‘We had the possible route, him running away.
‘The following day the CCTV was released to the public.
‘All the way through this elongated investigation with only a picture not a name, we asked the public for help a great deal.
‘The following day we managed to get the e-fit with the man with a beard. That went out extensively.
‘Through further work with phone data we managed to get an image from Barclays Bank.
‘That was then released to the public.
‘What’s really unusual about this investigation, is often when you’re running a manhunt you have a name and therefore if you look at that you have a risk assessment around them.
‘In theory you know who you’re dealing with.
‘You can ask for intelligence reports, all those pieces of information, and you can build up a picture.
‘That’s quite important looking at the risk they pose to people.
‘What we had here was a picture without a name.
‘Chasing a picture for a couple of weeks is very intense.’
The pressure surrounding the team – led by Det Chief Insp Williams but overseen by a Detective Superintendent with reports back to the chief officer group – was huge.
Reaction on the streets was one of upset and shock that a teenager could be attacked in such a way.
Police moved to reassure people, while at the same time asking for help.
A £5,000 reward for information was offered via Crimestoppers much earlier than would normally have been the case.
On April 20, the city’s district commander Supt Will Schofield appealed on video for help, while the day before an appeal was shown on the Big Screen in Guildhall Square.
A reconstruction was run of the suspect’s footsteps in Queen Street on April 23, while an appeal was also shown at Fratton Park.
At its most intense, 80 officers were working on the investigation at any one time.
Drawn from 15 units, all were determined to catch the attacker.
‘We didn’t know whether she was going to live or die for days,’ Det Chief Insp Williams added.
‘She had severe head injuries.
‘She has very little memory now of what happened.
‘A lot of very dedicated officers worked hard and at all hours.
‘It was my job to perk up the team and motivate them as well as investigate.
‘The team were very motivated.
‘It was a very human crime, and you could see the human tragedy.’
Eight days after the specialist super-recognisers were brought in on April 21, Hemming was declared a suspect at about 4pm on April 29 and arrested.
The final breakthrough had come after CCTV traced a vehicle, which was then linked to Hemming.
He was arrested just after arriving home from his job, where he works out of the county as a builder.
But the thought of him evading justice, staying a just a ‘picture’ had flitted across the minds of detectives.
Det Chief Insp Williams added: ‘It was one of many concerns.
‘I had considered a longer-term investigative strategy a couple of days before we got those breakthroughs.
‘Once you’ve got very positive and viable lines of enquiry that look like they’re going to be successful that changes your mindset.
‘It invigorates the team.
‘Once we got him arrested there was a huge feeling of relief.
‘He was arrested on the way home from work, he’d just got home.
‘From what we know he’d been carrying on his life as normal on a day-to-day basis.’
Major work continued, with a race against time to get forensics completed to link his DNA to the scene.
Led by a tactical interviewer, detectives quizzed Hemming for seven hours and 43 minutes over eight sessions.
He said little to police and gave no hint of motivation behind the attack.
Hemming was charged on May 1 with attempted murder but pleaded guilty to wounding with intent at Portsmouth Crown Court on September 8.
‘Super-recognisers’ helped track down suspect
POLICE renowned for recognising faces has been deployed in notorious cases.
The specialist unit has been used in the Alice Goss murder investigation and to hunt prolific thieves on CCTV.
In Portsmouth they looked at the footage, looking at the shape, build and even how the suspect walked.
Piece by piece, together with CID officers in the city, they helped find James Hemming in various images.
‘Their expertise is looking at CCTV images,’ Detective Chief Inspector Liz Williams said.
‘With this we were looking for people who fitted the description facially.
‘But also with this, once we tied down that the offender lived in a certain area, it was gathering those hours of footage and looking at following from one camera to the other.
‘So if you imagine you’re looking at a variety of camera angles, some better quality than others, it’s around the expertise of them knowing what they’re looking at.’
Investigators working on the case clocked 3,000 hours in additional duty time.