A woman allegedly changed her boyfriend’s son’s diaper ‘roughly’ and shook the infant so violently that he died.

Tiara Allen, 26, stated that she woke up before 7.30am on July 13 to warm up milk for her boyfriend’s baby and put his bassinet into their room and went to sleep for a few more hours.

Later in the morning, Allen said she put the infant, Conway, on the bed and went to the restroom and returned to find him making a fuss.

‘I tried to settle him down and nothing was working. I tried to give him his “binkie” and bottle and nothing was working,’ said Allen in a statement.

Tiara Allen has been charged with reckless assault of a child, endangering a child’s welfare, second-degree murder, second-degree manslaughter and first-degree assault (Picture: WWNY)

‘I picked up Conway and took my anger out on him and I shouldn’t have. I picked him up with both hands and shook Conway back and forth out of frustration and anger.’

She added that she ‘roughly’ changed Conway’s diaper and then ‘forcefully pushed’ his legs up.

After Allen finished changing the diaper, Conway became limp and appeared unconscious, she said.

‘I thought maybe me holding him and moving him back and forth could have done it,’ she stated.

Allen observed some blood coming out of Conway’s left nostril and sought help including from someone who called 911. Allen was advised to hold Conway belly down and cradle his head to see if he was choking but ‘that wasn’t working’, she said.

Conway suffered a bilateral subdural hematoma in his brain, according to court documents published by Law & Crime on Monday. The infant died in August.

Allen admitted she believed she caused his injuries.

‘I should have walked away from the situation and come back to him later, but it’s hard when he is fussy,’ she said in the statement she signed.

Allen was arrested on July 13 and charged with reckless assault of a child and endangering a child’s welfare. She faces new charges of second-degree murder, second-degree manslaughter and first-degree assault, according to records.

A grand jury in St Lawrence County, New York, indicted Allen on November 17.

Allen is scheduled to appear in court for a hearing on January 8.

She was indicted a month after a man was given two life sentences in prison for beating his girlfriend’s two-year-old daughter dead and refusing to call for medical help until the girl could not be saved.