Errors that let mother poison son

An extraordinary series of blunders allowed a mother to kill her son by spiking his hospital drip with salt.

Police, social services and Great Ormond Street hospital admit they all made mistakes which left the path clear for Petrina Stocker to kill.

A major independent review catalogued a list of more than 25 failings after Stocker, 42, poisoned nine-year-old David with 18 teaspoonsfuls of salt. It found that:

Stocker's case comes on the fifth anniversary of the death of Victoria Climbie, who died from abuse and neglect despite being seen by dozens of social workers, nurses, doctors and police officers.

All agencies in David's case said they are working to bring in a raft of measures to prevent a similar incident happening again.

David, from Romford in Essex, died at Great Ormond Street in August 2001 after his mother spiked his intravenous drip. She is said to have been suffering from Fabricated Induced Illness (FII), also known as Munchausen's syndrome by proxy, harming her son to seek attention for herself.

During seven months of hospital visits, David deteriorated into a sick, skeletal child weighing barely three stone.

Five months before his death David's drip at Oldchurch Hospital, Romford, was found to contain a white powder. Stocker put blood and Ribena into urine samples and manufactured vomit samples.

Doctors continued to look for a conventional diagnosis despite warnings from individual nurses and specialists - and though David's father Keith accused his wife of tampering with the drip.

Police, forced to wait on medical advice, did not launch a criminal investigation. Nearly all the early forensic evidence was thrown away. Mark Rees, chief executive

of Barking, Havering and Redbridge Hospitals NHS Trust, which manages Oldchurch Hospital, said: "There was a lack of staff training to recognise what was happening or know how to deal with it."

Havering social services chief Marilyn Richards admitted: "We made a serious mistake in that we didn't complete an assessment of David."

Detective Chief Superintendent Peter Spindler, Met head of child abuse investigations, said: "I accept we were probably not robust enough in the way we managed the investigation."

Great Ormond Street chief executive Dr Jane Collins said: "What we didn't do was to make sure the feeds could not be tampered with in any way whatsoever."