Police say a father stored an AR-style rifle in his young son's bedroom, leading to the boy accidentally shooting and killing his 5-year-old sister at a south Phoenix home on Tuesday night. On Wednesday, Phoenix police announced that 33-year-old Irvin Ramos-Jimenez was arrested in connection with the shooting. Officers were dispatched to an "unknown trouble" call around 9:15 p.m. near 6th Avenue and Wier Avenue, which is south of Broadway Road. Ramos-Jimenez called 911 and initially told investigators that his daughter had been stabbed. While officers were headed to the scene, they learned Ramos-Jimenez had driven off while rushing the girl to the hospital, family members said. Police found them near a psychiatric center near 7th Avenue and Buckeye Road to meet ambulances.