CHICAGO (CBS) — A 1-year-old boy was shot in the head on Monday night when his parents fought over a gun and it went off, police say. He was not wounded by a stray bullet on the street a block away, as his father had claimed.

Police said the boy’s father walked into Weiss Memorial Hospital with the baby boy shortly after 7:30 p.m. He claimed someone had opened fire at him near Clarendon and Leland avenues, and shot the boy instead.

However, investigators soon had trouble corroborating the father’s story. Chicago Police Department spokesman Anthony Guglielmi said Tuesday morning detectives have determined the father’s story wasn’t true.

Investigators found blood in an elevator of the father’s apartment building near Clarendon and Eastwood Avenues, a block away from where the father claimed the shooting happened on the street. Guglielmi said police also found at least one shell casing and blood in the kitchen and living room of the family’s apartment.

Detectives determined the parents were struggling over a gun Monday night, and it went off, and a bullet ricocheted and hit the boy in the head. The bullet did not penetrate his skull.

Guglielmi said police have seized surveillance video from the apartment building and are reviewing the footage as they question the boy’s mother and father. Investigators also are combing the area around Weiss Hospital, searching for the gun from the shooting.

No charges had been filed as of Tuesday morning, but Guglielmi said charges are likely.

The boy was transferred to Lurie Children’s Hospital after his father brought him to Weiss, and the baby was in serious but stable condition.

Tara Molina