Phoenix man allegedly killed 9-week-old baby

Police arrested a valley man for killing his 9-week-old baby.

Gilbert Salazar-Betancourt is behind bars on charges of murder and child abuse.

Court paperwork shows the boy suffered brain damage due to a medical issue at birth.

Doctors said there's evidence of "shaken baby syndrome" as well as skull and rib fractures

The baby's father denied injuring the child. He claimed he found the baby not breathing.

The incident happened in May and the infant died in July.