"Sickening and depraved" Delroy Grant is found guilty of 29 counts of preying on elderly men and women. Simon Israel looks at the police errors which saw the Night Stalker elude capture for 17 years.

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Finally it's over. Seventeen years of terrorising the elderly communities of south London and beyond has ended.

53-year-old Delroy Grant who became known as the "Night Stalker" has been found guilty of 29 offences ranging from rape to burglary from 1992 to 2009 at Woolwich Crown Court following one of the Metropolitan Police's longest ever manhunts.

But with today's verdict comes a public apology from Scotland Yard for squandering opportunities to capture Grant in the late 1990s before he went on to claim scores more elderly victims.

In total the Night Stalker was investigated over 203 incidents each representing a victim although he was convicted of just 29 offences involving 18 victims.

But Channel 4 News understands 146 of those people fell prey to Delroy Grant after May 1999 following the first police failure to catch him.

'Nocturnal predator'

The former mini cab driver turned full time carer for his wife is suspected of being responsible for many more crimes than just those he's been convicted for today. The Met's "Operation Minstead" team which toiled for 11 years to catch Grant believe the true figure is in the region of 200 offences, amounting to 128 victims in total. The vast majority were women aged between 68 and 93 and all living alone.

We are deeply sorry for the trauma suffered by all those victims and our failure to bring Grant to justice earlier. Commander Simon Foy

According to the prosecution, Grant was a nocturnal predator. He would survey homes, sometimes from the dark corners of back gardens. He would remove entire windows, disable phone lines, dismantle fuse boxes, turn off electricity supplies, and even unscrew light bulbs. He wore gloves, was meticulous and left little to chance.

Victims talked of having a torch in their faces and Grant would sometimes spend hours in conversation with them. Resistance scared him. Submission he took as an invitation to attack.

DNA evidence was to prove the undoing of a man who outmanoeuvred and outsmarted the Met's most senior detectives for nearly two decades.

Police mistakes

It was found at the scene of his first rape in 1992 and then in at least 11 other locations in the years to come.

But he wasn't captured until 2009 during a huge surveillance operation involving 70 officers. Grant was caught leaving one of the three cash machines he used to obtain money on cards he had stolen from his victims who he then terrorised into revealing the pin numbers.

But police had squandered two chances to get him ten years earlier back in 1999.

Delroy Grant

The first, Channel 4 News understands, was to follow up inquires on the owner of a car seen speeding away from a burglary in Bromley. A witness had noted the registration number. The burglary squad in Bromley sent all the information to the Minstead team set up to hunt the Night Stalker.

An officer visited Delroy Grant's home. He wasn't there but his disabled his wife produced the log book to confirm ownership of the vehicle. But according to an Independent Police Complaints Commission (IPCC) inquiry there was no follow up.

That inquiry fell between the two investigative units. Nothing was done. That officer appears to have just been doing a favour for his mate on the Bromley burglary squad with zero consequences.

The second chance can be only described as a muddle of information, wires which were crossed and remained crossed for ten years. Legal reasons prevent a detailed account of what exactly took place, but there was yet again confusion over a suspect with a similar name.

The errors meant Delroy Grant, who should have been top of the list of suspects in 1999, was ignored for all that time.

Today the IPCC published findings into the operation which found that "confusion" over the burglary response and the subsequent mix up with a similarly named suspect, led to a failure to arrest the sexual predator.

Police regret

The Met senior officer with overall responsibility for the inquiry, Commander Simon Foy said:

"We are deeply sorry for the trauma suffered by all those victims and our failure to bring Grant to justice earlier."

The police chief branded Grant a "perverted, callous and violent individual" who attacked some of the most vulnerable people in society.

His crimes were "some of the most awful and disturbing in the history of the Met," he added.

The mistakes themselves might appear very minor. Certainly no officer will receive disciplinary action. But the Met Police know only too well that the consequences of what appeared to be random systemic errors were disastrous. Hence the public apology.

And they were fortunate. Sources have told Channel 4 News the Minstead team were always fearful that sooner or later it would become a hunt for a killer.

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'I thought we'd never catch him'
Forensic scientist Raymond Chapman worked for 12 continuous years on the Night Stalker case as police tried to match suspects with samples of DNA found at a number of crime scenes.

Mr Chapman told Channel 4 News that after years of following the forensic profile of Delroy Grant across south London, he thought he'd never see the day when the predator was caught.

"We search for body fluids and DNA and we dealt with 100s of cases and in a lot of them we didn't find anything useful, but every now and then we'd find his profile," Mr Chapman from the Forensic Science Service in Lambeth told Channel 4 News.

"Over the ten or 12 years we could track this guy around south London [through samples gathered from crime scenes]. Sometimes we would go years without finding any DNA because he was very careful, but every now and then we'd find his profile and then we could tell the police this is part of the same series,"

Mr Chapman said there were times when he thought the attacker would never be caught.

"He seems to have been quite clever in evading the police so the case went on. I never thought I'd see an end to it," he said.

"I had assumed I would retire before we ever caught the guy. I think I would have remained very frustrated for a bit of unfinished business, so I'm really glad we've finally sorted this case out.

"It was an incredible moment when we finally saw that the profiles matched."

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