THE mother of a bright teenager described yesterday how she tried in vain to get her daughter off heroin before it killed her two days short of her 16th birthday.

Catherine Longstaff had been on the verge of sitting her GCSE exams and pursuing her dream of becoming a doctor when her mother, Olwen, discovered her dead in her bedroom.

An inquest into the teenager's death heard that Mrs Longstaff found out Catherine was taking heroin five months earlier.

"We tried everything we could to get her off it," she said.

Catherine, of Chatsworth Avenue, Bishop Auckland, County Durham, had not used the drug for some time before she took the dose that killed her.

On May 5 last year, Mrs Longstaff noticed Catherine had returned from an evening out with slurred speech. They arranged to go shopping for clothes for her school leavers' party before Catherine went to bed.

But the next morning she discovered Catherine dead in her bedroom with needle marks on her arm.

DC Tony MacDougal, from Bishop Auckland CID, said they had followed up a number of leads during their investigations. They had spoken to four people from the Bishop Auckland area believed to have been with Catherine before her death.

But he said they had exhausted all lines of inquiry and there was insufficient evidence to prosecute anyone.

South-West Durham and Darlington Coroner Colin Penna recorded a verdict of misadventure.

He said: "The tragedy is that sometimes nowadays 15-year-olds imagine they're adults or young adults, when they're still children and as children parents want to protect them from many of the problems which are endemic in society now."

In a statement released by Catherine's family after the inquest, they described their devastation.

"Cathy was a beautiful and talented girl and our very precious daughter and sister," they said. "She was much loved and is greatly missed by all her family and friends. Losing her has devastated our lives."

The family thanked the police for their efforts in combating the "ever growing drug problems" in Bishop Auckland and urged people to help police in their bid to stamp out drugs.

They added: "We would urge anyone with knowledge or information, that may help to prevent a similar tragedy, to assist in any way they can."

* Police have organised a drugs awareness evening for parents and carers at Parkside Comprehensive School in Willington on Tuesday April 30, between 7pm and 9pm.