A man murdered his young stepson by swinging him round by the ankles and smashing his head into a fireplace before lying about it for 50 years, a court has heard.
David Dearlove, 71, is accused of killing 19-month-old Paul Booth on Teesside in 1968 after the toddler's then three-year-old brother Peter claimed he had crept downstairs and witnessed the vicious attack through a crack in a door.
But despite Peter trying to get the police to reopen the investigation on three separate occasions, the case remained closed for five decades.
This changed when, in 2015, Peter became incensed by a picture posted on Facebook of Mr Dearlove, who now lives in Great Yarmouth, holding his younger brother and as a result gave an interview to the police.
Prosecutor Richard Wright told Teesside Crown Court on Tuesday that there was no doubt that a fractured skull had been the cause of Paul's death but that the jury needed to decide how it had happened.
Dearlove, who denies murder as well as manslaughter and three charges of cruelty, claimed Paul had fallen out of bed and struck his head on the floor.
Mr Wright said: "The police interviewed Peter as a witness for the very first time in 2015. He had not been asked to give any account in 1968.
"What he said in that interview is what has led us here, 50 years on, to the trial of David Dearlove for the murder of his stepson, Paul Booth.
"Peter told the police that the death of Paul was not the result of an accidental fall out of bed. He had in fact seen how Paul came to be injured when he had crept downstairs to get a drink that October night.
"Through a gap in the door into the sitting room he had seen David Dearlove swinging Paul Booth around whilst holding on to his ankles and had watched as his stepfather smashed the little boy's head into the fire surround, causing the fatal injury to his skull by the impact.
"The death of Paul Booth had been no accident, it had been as the result of a deliberate act. It had been murder."
The court heard that the boys' mother, Carol Booth, had three children, including a girl called Stephanie, and they lived in Haverton Hill, near Stockton.
Ms Booth, who is now dead, had started a relationship with Dearlove in early 1968.
Mr Wright said after Paul's death that doctors had found multiple bruises of "differing ages" and he had suffered numerous "non-accidental injuries".
He said: "There was therefore a substantial history of injuries being occasioned to Paul in a series of incidents prior to his death, often at a time when only David Dearlove was present and in charge of the child.
"This may be the important context in which to consider the circumstances of Paul's death."
The jury was told that Dearlove's abuse also allegedly extended to the two siblings, which account for two of the cruelty charges.
Mr Wright said Peter was "extremely scared" of him, due to being regularly assaulted, including being held under the water in the bath.
Stephanie also claimed that Dearlove would often lie on top of her in bed with his full weight and then slap her if she cried.
The case continues.