Updated

Five people died in a shooting Wednesday at a Phoenix-area home, where the investigation was slowed by concerns there could be hazardous materials in 55-gallon drums in the backyard.

The shooter was among the dead, police said, although they weren't yet certain whether he killed himself. Police haven't identified him or the victims.

Four of the bodies were still inside and outside of the home late Wednesday in the city of Gilbert, southeast of Phoenix.

At a briefing for reporters, Gilbert police Sgt. Bill Balafas said all the evidence points to the shooting being related to domestic violence. He didn't elaborate. Officers have recovered two handguns and a shotgun.

He said two men were dead outside the home and two women were dead inside. A girl between 1 and 2 years old was found inside the home showing signs of life when police initially responded to the scene, but she later died at a local hospital.

Balafas said authorities have not gone into the home since then as they awaited a search warrant and later for a federal agency to remove unknown chemicals and munitions from inside and outside of the home for officer safety.

He said positive identifications of the bodies can't be made until detectives can safely enter the home.

About three hours after the shooting, a man walked up to the police tape, pointed to the crime scene and said, "I have a daughter who lives in that house."

Police pulled him behind the tape and out of view. Several seconds later, a loud, anguished cry could be heard. Minutes after, the same man was weeping and left the scene with police.

The shootings occurred after 1 p.m. in a subdivision filled with stucco homes with red-tile roofs.

Witnesses said a SWAT team sealed off part of the area and investigators told residents to remain indoors.

FBI spokesman Manuel Johnson said federal agents were at the scene "providing personnel and technical assistance" to Gilbert police, but that the police department was the lead agency.

DeAnn Rawson, who has lived in the Lago Estancia neighborhood for 13 years, stood on a street corner and talked to drivers who rolled down their windows to ask what happened.

Rawson, 38, said she was sick to her stomach over what happened. "As you can tell, everyone driving by is absolutely shocked," she told The Arizona Republic.

"I would have come and got her," Rawson said of the youngest victim. "It makes me mad. I can't have children, and you have other people doing things that are insane."

Gary Davis, who also lives in the neighborhood, said, "There's no excuse for taking a child's life."

"Nothing ever happens in this neighborhood," Davis said. "It's a shock to us."