A man who allegedly gave an infant anti-depressants after becoming angry and frustrated with his crying is now on trial for the 21-month-old's death.
Cecil Patrick Kennedy, 51, has pleaded not guilty to the manslaughter of toddler Jordan Thompson in the rural NSW town of Singleton.
Kennedy had been in a relationship with Bernice Swales for four or five months when her young son died at his unit on March 19, 2005.
Jordan had been sleeping all day and had not been his usual active self when Ms Swales popped out to the shops for an hour, leaving Kennedy in charge of the infant.
On her return, she heard Kennedy screaming and found her son naked and unresponsive on the bed, crown prosecutor Kate Nightingale told the NSW District Court jury on Tuesday.
Kennedy allegedly told Ms Swales the infant had injured himself by falling either into or out of the bath.
On the same day, he told police he had given the child a bath but had left him unattended in the tub for around a minute, returning to find him face down in the water.
Ms Swales took her son to Singleton Hospital across the road from the unit complex. Medical staff were unable to revive him and he was pronounced dead.
While an autopsy did not determine the cause of Jordan's death, blood analysis revealed high levels of the anti-depressant drug amitriptyline, sold under the brand name Endep, which Kennedy had a prescription for.
Amitriptyline was also detected in the toddler's bathwater, his nappy and some vomit on his clothing after the child was sick in the hours before his death.
There were no signs that Jordan had drowned, and his skin and hair were dry when he was admitted to hospital, jurors heard.
However, drowning itself could not be excluded as a cause of death.
Police located a box of Endep in a paper chemist's bag on a bedroom closet shelf within Kennedy's unit after he had been prescribed the medication in February 2004.
Jurors will have to determine the cause of Jordan's death which include amitriptyline toxicity or that the toddler was under the influence of the sedative which contributed to his death by drowning.
In phone calls intercepted by police, Kennedy suggested Jordan could have obtained the medication from his biological father Paul Thompson who he visited a few days before his death or that he may have found a tablet on the floor of his apartment and swallowed it.
The jury heard Ms Swales would give evidence that Kennedy was cranky and "pissed off" on the day Jordan died and that he became irate when the child cried.
While Kennedy told police he did not phone an ambulance because he had no credit, investigators discovered that he had $15-worth on the day of the tragedy.
Ms Nightingale said Kennedy had lied a number of times to police, including why he left Jordan in the bath and his suggestions the toddler could have obtained Endep some other way.
Defence barrister Linda McSpedden briefly spoke to the jury, urging them to keep an open mind and listen to all the evidence.
"This accused man has denied being responsible for the death of Jordan and please keep your minds open in that regard," she said.
The trial in front of Judge William Fitzsimmons continues.
