ONE of Scotland's youngest sex killers was given a life sentence yesterday for the murder of a handicapped woman.

Catriona McLean, 55, was found sprawled on the floor of her home in Glasgow just days after Christmas 2001 when her murderer, Richard Clark, was only 14.

Last month Clark, now 16, from Parkhead in Glasgow, was found guilty of indecently assaulting Miss McLean, who suffered from cerebral palsy, and smothering her to death with a pillow and duvet.

He was also found guilty of stabbing Miss McLean and spraying her with an unknown substance.

It was this spray that eventually led to his conviction, as it left a tell-tale footprint on the floor of Miss McLean's home when he stepped across her body to make his escape.

Experts told the High Court trial that the footprint matched the pattern of Clark's trainers. His fingerprints were also found in the flat in Muiryfauld Drive, although Clark claimed this was because he regularly visited the woman, who was a friend of his family, and ran errands for her.

However, a police reconstruction revealed that the position of the fingerprints on the door were exactly where Clark would have reached out to steady himself as he stepped over the body.

Miss McLean was discovered by Clark's aunt on the morning of December 28, 2001. Her clothing had been disturbed and her breast was exposed.

Originally, the teenager was charged with raping Miss McLean, but a jury later found him guilty of indecent assault.

When Clark returned to court yesterday in Edinburgh to be sentenced, Lord Wheatley added his name to the sex offenders' register.

The judge also ordered him to be detained without limit of time, telling him he must serve at least eight years before he can apply for parole. Lord Wheatley said he was fixing the eight-year period because of the teenager's age.

Miss McLean, who used a Zimmer frame to walk, was mostly confined to her home. A post-mortem examination failed to reveal the cause of death.

It was more than a month after the attack that a murder hunt was launched.

During the trial, Clark claimed that someone else was responsible for the murder, but when the jury returned its majority guilty verdict he collapsed forward in the dock and put his head in his hands. His parents and family members sat shaking their heads. Jack Davidson, defence QC, said yesterday that Clark still maintained his innocence.