A young father, whose five-week-old daughter died after suffering a brain haemorrhage, has admitted manslaughter.
Andrew Ashurst was warned he faces a substantial prison term
Leah Aldridge died in Royal Manchester Children's Hospital on Christmas Day 2002, two days after being admitted with breathing difficulties.
A post mortem examination showed she died from brain and retinal bleeding.
Andrew Ashurst, 22, of Atherton, Greater Manchester, pleaded guilty at Liverpool Crown Court and will be sentenced later in May.
The court heard that Ashurst had admitted causing his daughter's death at their home on Blake Avenue but claimed not to know how her injuries happened.
But Ashurst accepted that they had occurred while she was in his care.
The court was told that in the week before Christmas, Leah, who was otherwise healthy, had become unwell with a cold that disrupted her sleep.
In the early hours of Monday, 23 December, Ashurst took her downstairs to try to settle her.
But when he handed Leah to her 16-year-old mother, Janine, later that morning, the baby was limp and struggling to breathe.
Andrew Edis QC, prosecuting, said: "The fatal injury may have resulted from a single violent act, although on the basis most favourable to the defendant, it must have involved a severe shaking of this child.
"Although the defendant denied using violence when interviewed he now pleads guilty to manslaughter saying he did not intend to cause really serious harm."
Leah was taken to the Royal Bolton Hospital and later transferred to the children's hospital where she died.
Ashurst was remanded in custody to be sentenced on 27 May.
The judge, Mr Justice Morland, who ordered pre-sentence reports, warned Ashurst that he would inevitably pass a substantial prison sentence on him.
Following the hearing, Detective Sergeant Lyndon Wright, from Leigh CID, said: "This has been a traumatic event for everyone involved but especially Leah's mum.
"At only 16, she has already seen more heartbreak than most of us will face in a lifetime.
"Not only did she lose her healthy young baby through no fault of her own, but someone that she trusted to be responsible for her child has then caused her death."
He added: "Greater Manchester Police will continue to seek prosecutions against anyone who believes they can harm, neglect or ultimately kill helpless young infants."