WARSAW, Ind. (AP): A northern Indiana man who authorities say fatally beat his girlfriend’s 2-year-old daughter and then buried her body in a shallow grave has reached a plea agreement in the case.

WSBT-TV reports a hearing is scheduled for Monday on Christopher Grimmett changing his plea to guilty but mentally ill in the death of Adalin Stamper.

Authorities say the Warsaw man beat Adalin and buried her body in November behind his brother’s home. An autopsy determined the child died from multiple blunt force injuries.

Grimmett’s attorney says an agreement calls for a 50-year sentence. A motion to seek an insanity defense was filed earlier this year in the murder case.