(NBC)- An Arizona man is accused of killing four people, including his wife and two of their children, and injuring two others in what police said began as a domestic dispute after he accused his wife of having an affair.
The 30-year-old suspect, who has yet to be identified, allegedly murdered his wife, 29, and their two daughters, ages 7 and 5, at their Phoenix home, Sgt. Tommy Thompson of the city's police force said at a news conference Friday.
The police sergeant said it is tough emotionally for investigators when young children are the victims.
"Anytime we deal with small children, or children for that matter, it's an added burden," Thompson said.
The man chose not to kill his 3-year-old daughter, who was found by police hiding under a bed, Thompson said.
Police have not described the cause of death for the wife and the other two children, whose bodies were found Thursday night.
After allegedly killing his family, the suspect drove to an apartment complex in Phoenix where he fatally shot a 46-year-old man he believed had been sleeping with his wife, according to police.
The suspect told officers during an interview "that the reason he shot these individuals is because in God's eyes, it was all right for him to deal with someone in this manner who had been involved in an extramarital affair," Thompson said.
Two other people, a man and a woman, were also shot at the apartment. The woman, who is related to the deceased male victim, was hospitalized in critical condition.
Police were alerted to the murders around 8:18 p.m. Thursday when they received a call about a shooting at the apartment complex. When officers arrived, they saw a car they believed was being driven by the shooter leaving the scene.
The car was stopped and the suspect was taken into custody. One of the injured victims told police they were worried about the suspect's family and asked officers to perform a welfare check.
Authorities believe the suspect killed his family first before going to the other location. Police are not releasing the identities of any of the victims until family members have been notified.
The suspect's name will be released after he is booked into jail, police said.