Jurors deliberated about four hours on Tuesday before finding 20-year-old Joshua Mauldin guilty of felony injury to a child.

After the verdict, they deliberated Mauldin's punishment for 2 hours without a decision. They were set to resume working on Wednesday. Mauldin faces anything from probation to life in prison.

Mauldin pleaded not guilty by reason of insanity, saying he was having a psychotic episode when he put his then 2-month-old daughter, Ana, in a hotel microwave for 10 to 20 seconds last May while her mother and grandmother were away.

Prosecutors and Mauldin's defence attorney, Mr Sam Cammack III, had no immediate comment after the verdict.

Mauldin sat emotionless as his daughter's foster mother detailed in penalty phase testimony how Ana's wounds still need to be cleaned every day and how she screams during the painful process.

The witness, Ms Heather Croxton, said she hopes to adopt Ana, who is now 1 year old. Another trial scheduled for next month will seek to terminate the parental rights of Joshua and Eva Mauldin, who lives in Arkansas. Ms Croxton's husband is a step-cousin of Eva Mauldin.

Ms Croxton said Ana will need more operations to remove scar tissue and reconstruct her left ear, but she said she is more worried about the day Ana finds out what happened to her.

'I can only imagine how (she) would feel, knowing that the man that was supposed to take care of her did this to her,' Ms Croxton said as she cried. 'As far as telling her the truth ... I don't see how we cannot tell her. She's going to want to know how she got those scars.'

Mr Cammack told jurors during closing arguments on Monday that mental illness was probably the only explanation for his client's actions.

'Joshua Mauldin has been somebody with mental illness from the time he was 10 years old until the time this offence was committed,' he said.

But prosecutors countered that Mauldin was driven by anger that he was in a loveless marriage and was stuck in a new town with a baby he didn't want to care for.

'All (Mauldin) has done is try to wrap himself in some psychiatric flag and say, 'I did it and I was crazy',' Galveston County prosecutor Xochitl Vandiver told jurors. 'That's what he's trying to pull on you all. Don't fall for it, because it is a lie.'

Officials say Ana suffered second- and third-degree burns to her left ear, cheek, hand and shoulder and needed skin grafts. Before putting her in the microwave, Mauldin had punched the baby and put her in the hotel room safe and refrigerator. -- AP