THE mother of murdered prostitute Carly Bateman today issued a chilling warning to all parents "There is a bigger killer out there."

As Geoffrey Porter began a life sentence for strangling the 17-year-old drug addict, her mum Vanessa Stirling warned: "You don't know when heroin will come knocking on your door."

Porter was convicted by a jury of murdering the teenager whose naked body he dumped in an alleyway on the outskirts of Bolton's red light district.He showed no emotion as the jury of five women and seven men returned their unanimous verdict after a two week trial at Manchester Crown Court.

Judge Mr Justice Holland told Porter, who has previous convictions for indecent assault, that he was a danger to young girls and he was going to pass on his concerns to the Home Secretary. Mrs Stirling, aged 49, was in court to hear the verdict with Carly's father Alan Bateman, aged 45, her sister Lianne, aged 22, and 28-year-old brother Simon. She said: "Carly can rest in peace now but there is a bigger killer out there.

"I am glad that Porter is now behind bars, and is no longer a danger to women.

"I hate him but it won't bring Carly back. Nothing will. There was only one verdict - guilty - and I am positive justice has been done.

"But heroin and cocaine are still out there, and other teenagers who are taking these drugs are putting themselves in danger and they need to realise this. No child is safe. You don't know when heroin will come knocking on your door."

She described the family's battle to keep her daughter off drugs. "We did everything we could to help Carly, and social services also went above and beyond the call of duty in trying to help her. Carly was very intelligent and had so much going for her. She was a lovely, loving child.

"It makes me feel so desperate about all the wasted potential. I have spoken to many parents who have lost their only child to drugs - at least I have two lovely children and three grandchildren left.

Det Chief Insp Tony Cook who led the investigation said: "Porter has never admitted he was responsible and has never shown any remorse.

"Carly's death was a tragic end to what had become a sad life.

"To some people Carly was just a prostitute, but to us she was a victim of one of the worst crimes anyone can commit. I am grateful to those people who came forward with information, and helped us catch this young girl's killer."

Porter, aged 40, of Columbia Road, Bolton, had denied murder and despite DNA evidence linking him with Carly, he claimed he could not remember having sex with her that night.

Her body was discovered in an alleyway off Crawford Avenue, The Haulgh, at about 3.30am on November 11.

Tyre marks matching Porter's Proton car were found at the scene and fibres from Carly's naked body also matched some found in the vehicle. She has been killed after getting in his car for sex.

After, he dragged her body out of the car and hid it in undergrowth and dumped her clothes in a skip.

Carly is believed to have struggled as Porter strangled her with a ligature.