A toddler was killed after months of being physically abused by his stepfather, prosecutors have said.
Charlie Roberts was 22 months old when he collapsed with a "catastrophic" head injury at his home in Darlington in January, Teesside Crown Court heard.
Christopher Stockton, 38, denies murder and child abuse, while Charlie's mother Paula Roberts, 41, denies child neglect.
Ms Roberts bought a spy camera over concerns about Mr Stockton and her son but failed to take any further action to protect him, it is alleged.