A Trafford man has pleaded guilty in the 2020 death of his girlfriend’s infant son.

Thomas Anthony Glenn, 32, was initially charged with felony murder in the slaying of 5-month-old Isaiah Noel.

He pleaded guilty April 29 to a reduced charge of manslaughter and was sentenced to 20 years in prison, according to court records.

Per the plea agreement, Glenn surrendered to the Blount County Tuesday to await transfer to the Alabama Department of Corrections.

Isaiah was pronounced dead May 27, 2020, at St. Vincent’s Hospital-Blount.

The investigation showed that Glenn was dating Isaiah’s mother and would watch him while the mother worked.

Court records show Isaiah died from trauma to the brain after he was shaken.

“Based on the facts of the case, we are pleased that Mr. Glenn took responsibility for his actions with his guilty plea,’’ said Blount County District Attorney Pamela Casey. “My office will continue to fight for those that cannot fight for themselves.”