OSKALOOSA, Iowa (AP) — A November trial has been scheduled for a man accused of killing his girlfriend’s baby son in Oskaloosa. Mahaska County District Court records say 21-year-old Johnny Dale Jr. filed written pleas of not guilty Monday to a charge of first-degree murder and child endangerment resulting in death. His trial is set to begin Nov. 19.

A criminal complaint says Dale was watching the 4-month-old boy when his girlfriend went to work on June 15. She told an investigator the boy had a bruise on his forehead and wouldn’t wake up when she got home. Doctors later told investigators the boy had suffered brain and spinal cord injuries consistent with child abuse.

The complaint also says Dale said he’d grown frustrated with the baby and said he bounced him on an air mattress in an attempt to get him to sleep.