DNA profiling used to track rapist

Investigators tracking the Night Stalker used cutting-edge techniques to try to build a picture of the man from his DNA.

Several samples were recovered from attacks but because Delroy Grant was not on the DNA database police could never identify him.



This was despite the fact he had a significant criminal history, with convictions including attempted robbery and handling stolen goods.



As a result, police turned to a company based in Florida to help them build a picture of their suspect's ancestry.



The value of the expensive lab work and analysis remains disputed, even among detectives.



Scientists found Grant was of Caribbean origin and further work claimed his ancestors probably came from the Windward Islands.



After his arrest, police found Grant was Jamaican and have yet to find any links to the Windward Islands.



Eight police officers travelled to the chain of Caribbean islands, which include Trinidad, Tobago, St Lucia and St Vincent, as part of the inquiry.



Detective Superintendent Simon Morgan, who led the inquiry from 2001, said police focused on the DNA as victims gave limited and conflicting descriptions of Grant.



He said: "We kept up to pace with the world of science and technology that was developing DNA analysis and looked at what this could tell us about this offender.



"A sample was sent to Florida for ancestral analysis. The results were blind tested by experts in the UK. At the time, a limited number of experts existed in the world.



"They agreed that the interpretation of the analysis that his ancestry from five generations previously was Caribbean.



"This was effectively the time of the America slave trade. A mathematical presumption was that his ancestors were from the Windward Islands in the southern Caribbean.



"We now know he was born in Jamaica but we do not know his ancestry. The benefit of this ancestral work is that we were able to rule out thousands of individuals of African origin that were clearly not our priority."



Meanwhile, a move to collect DNA samples from more than 3,000 suspects sparked controversy and resentment among the black community.



Senior officers later admitted that the voluntary DNA testing did little to further the inquiry as 5,200 potential suspects remained on the system.



As the investigation went on police were swamped with information as they amassed details of 27,000 people on their database.



Police saw a similar lack of success with a steady stream of profilers and criminal psychologists brought in to give an insight into his lifestyle.

Start your day with The Independent, sign up for daily news emails
Latest stories from i100
SPONSORED FEATURES
Have you tried new the Independent Digital Edition apps?

Day In a Page

The long walk west: they fled war in Syria, only to get held up in Hungary – now hundreds of refugees have set off on foot for Austria

They fled war in Syria...

...only to get stuck and sidetracked in Hungary
From The Prisoner to Mad Men, elaborate title sequences are one of the keys to a great TV series

Title sequences: From The Prisoner to Mad Men

Elaborate title sequences are one of the keys to a great TV series. But why does the art form have such a chequered history?
Giorgio Armani Beauty's fabric-inspired foundations: Get back to basics this autumn

Giorgio Armani Beauty's foundations

Sumptuous fabrics meet luscious cosmetics for this elegant look
From stowaways to Operation Stack: Life in a transcontinental lorry cab

Life from the inside of a trucker's cab

From stowaways to Operation Stack, it's a challenging time to be a trucker heading to and from the Continent
Kelis interview: The songwriter and sauce-maker on cooking for Pharrell and crying over potatoes

Kelis interview

The singer and sauce-maker on cooking for Pharrell
Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

Cameron lowered the flag for the dead king of Saudi Arabia...

But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Humanity must be at the heart of politics, says Jeremy Corbyn
Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

Joe Biden's 'tease tour'

Could the US Vice-President be testing the water for a presidential run?
Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

Britain's 24-hour culture

With the 'leisured society' a distant dream we're working longer and less regular hours than ever
Diplomacy board game: Treachery is the way to win - which makes it just like the real thing

The addictive nature of Diplomacy

Bullying, betrayal, aggression – it may be just a board game, but the family that plays Diplomacy may never look at each other in the same way again
Lady Chatterley's Lover: Racy underwear for fans of DH Lawrence's equally racy tome

Fashion: Ooh, Lady Chatterley!

Take inspiration from DH Lawrence's racy tome with equally racy underwear
8 best children's clocks

Tick-tock: 8 best children's clocks

Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
Charlie Austin: Queens Park Rangers striker says ‘If the move is not right, I’m not going’

Charlie Austin: ‘If the move is not right, I’m not going’

After hitting 18 goals in the Premier League last season, the QPR striker was the great non-deal of transfer deadline day. But he says he'd preferred another shot at promotion
Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea