A Sydney man accused of drowning an 18-year-old alerted a family member to the death with a 5am knock-on-the-door and the words "Steven's sick … I think he's fitting", a jury has heard.
Merrylands man Charlie Younes, 45, has pleaded not guilty to murdering his former partner Rebecca Horton's son, Steven Copo, in an Emerton home in October 2013.
The boy had drowned in the bathtub.
Ms Horton's mother, Lynette Horton, on Wednesday said Mr Younes arrived at her door shortly after 5am.
"He said 'Rebecca needs you … Steven's sick' and he said 'I think he's fitting'," she told the NSW Supreme Court trial.
The trial continues.