JACKSON, Mich. — A jury has convicted a southern Michigan man of killing his ex-girlfriend’s 18-month-old son.

Scott Jurewicz was found guilty Friday of felony murder and first-degree child abuse in the March 2015 death of Brenden Hartranft. The Jackson Citizen Patriot reports that Jurewicz admitted he gave the child a “good shake” and put him down hard in a play pen in the home the couple shared in Michigan Center, near Jackson.

Chief Assistant Prosecuting Attorney Kati Rezmierski said Jurewicz “was going to win that battle” and “shut that kid up.”

Jurewicz is scheduled to be sentenced to life in prison on Jan. 4.