IT was a terrifying stranger rape that remained unsolved for two years, until the attacker struck again.

And remarkably it was this grainy CCTV image that triggered a sequence of events which was to ultimately lead to the rapist's capture almost two years to the day after his first attack.

Abdi Ahmed was jailed for nine years after he was convicted of raping a mother of three in 2004 and a teenage man almost exactly two years later.

Ahmed, 43, of James Street, showed no emotion as Judge Christopher Leigh delivered the sentence telling the machine operator: "You are a dangerous man.

"Further offences could happen at any time and the consequences inevitably could be most serious. Both males and females are at risk of serious harm."

Remarkably the Somalian national maintained his innocence throughout the trial despite a DNA match that proved the vital piece of evidence that linked him to both crimes.

"It is the fact that he was and still is in compete denial about either attack that in my opinion makes him very dangerous,'' said Det Insp Dave Dilley who led the recent investigation.

Speaking to the Daily Echo Det Insp Dilly described how justice finally caught up with Ahmed who had remained at large since he first struck in May 2004 when he attacked a 24-year-old woman who walked past his St Mary's home.

Southampton Crown Court heard how he was smoking a cigarette outside his former address at Alfred Street when he decided to follow the woman before grabbing her and dragging her to a car park behind the Royal South Hants Hospital where he raped her.

Det Insp Dave Dilly said: "The original case had lain dormant after inquires at the time didn't manage to find him.

"The DNA sample that was recovered from the victim was sent for analysis but no matches were found.'' The trail went cold and the investigation was wound up.

However, it was unexpectedly reignited when detectives sent off DNA for analysis that was recovered from the second victim.

"We sent it off and while it didn't come back with an identification match it did come back with a match on the previous case. It was then we knew we had a serial rapist on our hands,'' said Det Insp Dilly.

The 19-year-old victim was attacked after leaving the Edge nightclub, popular with the gay community in the city.

Described in court as being drunk "almost to the point of passing out'' the victim was only able to give police limited details of what happened on that night in May 2006.

Det Insp Dilly said: "We had great support from The Edge and CCTV footage was obtained from them.

"When detectives went through it with staff one security guard pointed at a shadowy image, identifying him as a man who he had seen hanging around outside the club regularly.

"It started a sequence of events that led to Ahmed's arrest.

"A week after the rape we had an officer working inside the club speaking to people inside to see if anyone saw what had happened.

"While he was in there the doorman said the man who had been spotted on the CCTV was hanging around outside again. The officer called for back up and he was arrested.'' A DNA sample was taken from Ahmed and within 24-hours he was confirmed as a one billion to one match.

Judge Leigh also recommended Ahmed be deported on his release.

"It is to this country's detriment if you stay here,'' he said.