The family of a mother questioned over the murder of her two-year-old son were so concerned about her behaviour they took her to hospital the day before she carried his lifeless body into a police station, it emerged today.
Melanie Ruddell, 39, was taken to Hartlepool General Hospital on Sunday by relatives and was later allowed to leave.
The following morning Mrs Ruddell, who is believed to have split from her husband several months ago, walked into a County Durham police station, carrying her son Christy.
Police quickly realised something was wrong and as the little boy was rushed to hospital, Mrs Ruddell was arrested.
Detectives believe Christy had been dead for some time before his mother took him to the police station.
A post-mortem examination at Sunderland Royal Hospital revealed the toddler had been strangled.
Police said the mother had injuries to her arms which are thought to have been self-inflicted and late last night she was taken to hospital for medical treatment.
She remains in hospital and detectives hope to speak to her once they are given permission to do so by medical staff.
Superintendent Rob Coulson, of Durham Police, said: "While I am not in a position to comment on any medical issues, what I can say is she is described by family and friends as a doting mother.
"She had difficulty leaving Christy with baby-sitters to go out.
"She's described as playing football in the back garden with him the Sunday before his death.
"What we really need to understand and establish is how can she go from (being) a doting mother to these tragic circumstances.
"What could cause that?"
A spokeswoman for North Tees and Hartlepool NHS Trust confirmed Mrs Ruddell attended Hartlepool General Hospital on Sunday.
"I cannot give out any more details due to clinical confidentiality," she said.
Detective Superintendent Adrian Green, who is leading the investigation, added: "This is a tragic incident which obviously has left both families concerned extremely shocked and distressed.
"While we are not looking for anyone else in connection with the murder, we would like to hear from anyone who has information which might be useful."
Neighbours of Mrs Ruddell, who is estranged from her husband Alan, in Castle Eden, near Peterlee, spoke of a loving mother.
Yesterday a former neighbour, who lives in the centre of the village, said Mrs Ruddell and her husband moved to the other end of Castle Eden about two years ago.
He said: "After she moved I really didn't see much of her other than when I saw her walking Christy around.
"She was vivacious. She enjoyed life."
The man, who did not want to be named, said he understood Mr and Mrs Ruddell split up some months ago.
"They left here and moved up to the other end of the village and as far as we were aware they were getting on well," he said.
"Something must have changed."
He added: "It is quite distressing to hear, especially to have heard it as a news item, with her being so doting and the child being so important to her.
"It is a big shock."
His wife said: "It is really shocking, horrible. We lost touch. We knew them well when they lived here.
"She had a very bubbly personality.
"Melanie wanted children. Having a child was so important to her.
"They were overjoyed when they had a baby."
Mrs Ruddell is understood to have worked as a welder for a local firm but after being made redundant began selling office stationery for a firm based on Teesside.
Another neighbour said: "She was a lovely, lovely person.
"Something very unfortunate must have happened.
"I am sure we'll find out in the fullness of time."