A Newcastle man accused of murdering a six-month-old baby has said he lied to police to protect the child’s mother despite admitting the pair only had a casual relationship where they met for drugs and sex.

Jie William Smith, 31, told his trial on Wednesday that the mother had punched the baby in the face on the evening of February 8, 2019 but that he had lied to police about the injuries because he felt sorry for her.

Crown prosecutor Neil Adams SC questioned why Smith would be prepared to face the serious consequences of being convicted of murder or manslaughter for a woman who he was only casually dating and to whom he routinely sent abusive text messages to.

“You say, do you, that faced with that, you agreed to cover up to protect this women with whom you had the most casual of relationships?” Mr Adams asked.

“Yep,” Smith replied.

He raised the alarm about the child with neighbours early on February 9, 2019. After an ambulance arrived, the baby was taken to hospital with extensive bruising and went into cardiac arrest early that morning.

In his earlier statements to police, Smith said he had accidentally dropped the child.

He pleaded guilty to manslaughter accepting he should have sought medical help earlier, but the Crown rejected this.

Giving evidence in the Newcastle Supreme Court, Smith claimed that after driving around to buy  the drug ice on February 8, he returned to his aunty’s home in New Lambton. After the baby started crying, he said the mother grabbed the baby under his arms and punched him four times.

After the attack, he intervened by grabbing the woman and telling her not to do that to her son in his aunt’s home.

Told that this was a “pretty mild response” to what had just happened, Smith stood by his evidence, saying that was his reaction.

He claims the mother then left him with the injured baby after taking the ice which had been divvied up between them.

“What were you going to do with a bleeding child?” Mr Adams asked.

“Look after him,” Smith replied.

Despite claiming the baby refused to stop crying throughout the night, a text sent by Smith told his casual girlfriend that her son was asleep.

He told the jury that he did not want to stress her out about her son’s condition. 

“You seriously expect the jury to believe, do you, that you didn’t (say something to the mother) because you didn’t want her to stress about what happened?” Mr Adams said.

The barrister took Smith to prior text messages in which he called the woman a “little putrid c***” as evidence that he had not previously cared about her feelings or held back from saying what he really thought.

Smith told police that he was covering up for the woman while in custody in June 2019, saying that he thought she would have come forwards with the truth by then. 

Mr Adams pointed out that Smith had also referred to the woman as a liar repeatedly in his text messages to her.

“What made you think she was going to come clean if she was, in your view, a liar?” the barrister asked.

“I don’t know, um, to take responsibility for her actions,” Smith said.

The trial in front of Justice Helen Wilson continues.