FORT WORTH, Texas (AP) — A 24-year-old Fort Worth man has been sentenced to life in prison without parole for the 2015 fatal beating of his girlfriend's toddler son.

Christian Tyrrell was convicted Thursday in Fort Worth of capital murder in the death of 2-year-old Adrian Langlais. Prosecutors say Tyrrell smashed the child's head against a wall.

Officials say the boy was admitted to a hospital on his second birthday, March 18, 2015, and died the next day. His 21-year-old mother — Jessica Langlais — was indicted on a capital murder charge in May and remains jailed.

Prosecutors did not seek the death penalty for Tyrrell, who testified Langlais caused her son's injuries.

Tarrant County District Attorney Sharen Wilson said in a statement Thursday that Tyrrell was "not fit to be a member of society."