A detective who helped the family of one of the murdered Soham schoolgirls has been jailed for conspiring to pervert the course of justice.
Brian Stevens and Louise Austin denied concocting the alibi
Cambridgeshire Det Con Brian Stevens, 43, gave a false alibi when he was accused of downloading child porn on the internet.
He was jailed at the Old Bailey for eight months.
His friend, Louise Austin, was jailed for six months, suspended for two years, for the same offence.
Stevens lied to police by saying he was with Crown Prosecution Service case worker Austin, 32, when the images were taken and that he did not have his computer with him.
She gave a statement to police supporting the alibi.
The jury of five women and seven men at the Old Bailey returned guilty verdicts on Friday.
Stevens had been a family liaison officer for the family of murder victim Jessica Chapman.
In the witness box, Stevens spoke of his intimacy with the Chapmans as
he tried to present himself as an honest police officer.
The allegation against him stemmed from an earlier case in which he had been accused of downloading indecent pictures of children on 9 June.
At the time, he had been undergoing treatment for a foot injury at the police rehabilitation centre, Flint House, in Goring-on-Thames.
Stevens was arrested at his Cambridgeshire home in September 2002, after his name came up in Operation Ore, a UK-wide trawl of internet paedophiles.
Indecent images of children were found on his laptop but the court case was dropped for reasons that had nothing to do with the alibi.
Following his arrest, Stevens denied all knowledge of the child porn, saying the computer had been with him at Flint House but that he had allowed other people to use it.
'Conspiracy in action'
But he later changed his story, telling police he did not have the computer with him at Flint House.
Instead, he claimed to have spent the night more than 100 miles away at Louise
Austin's home comforting her after she was dumped by her married boyfriend.
On 14 August, 2003, six days before his trial over the computer porn was due to start, Austin provided a
witness statement confirming that he had been at her house when the images were
said to have been downloaded in the police headquarters.
During the trial, the prosecution produced evidence, including mobile phone
records and credit card transactions that proved Stevens had in fact been in the area of Goring-on-Thames and nearby Windsor when the alibi said he was at
Prosecutor Peter Joyce QC said there was "a blizzard of communication" by
telephone between the pair from 1 May to 21 August, 2003, which showed "the
conspiracy in action".
A statement from the Chapman family said: "We would like to express our sense of huge disappointment in Brian Stevens.
"We asked him to read a poem on our behalf at the celebration of life service at Ely Cathedral.
"Now, seeing him convicted, has forever tainted what should have been a poignant reminder of our daughter Jessica's life.
"The use of our grief as part of Brian Stevens' defence in this trial has left us with a sense of betrayal.
"However, the rest of the team have restored our faith throughout an incredibly harrowing time."
Stevens, who was suspended from his job, now faces disciplinary action and could be sacked.
Det Supt Paul Craig, head of professional standards at
Cambridgeshire Police, said internal disciplinary proceedings were underway.