GILBERT, Ariz. (AP) Police on Thursday identified one of the five people killed in a shooting in a Phoenix suburb as a former Marine with ties to neo-Nazi and Minutemen groups.

Jason Todd Ready, 39, organized a militia in the Arizona desert with the goal of finding illegal immigrants and drug smugglers.

Known as "JT," Ready outfitted himself with military fatigues, body armor and gas masks, and carried assault rifles during patrols for illegal immigrants in the desert south of Phoenix.

The four others killed in Wednesday shootings in a home in Gilbert include 16-month-old Lily Lynn Mederos, 23-year-old Amber Nieve Mederos, 47-year-old Lisa Lynn Mederos and 24-year-old Jim Franklin Hiott.

Media reports that Lisa Mederos was Ready's girlfriend and Amber and Lily were her daughter and granddaughter.

Police have said the gunman was among the dead but have not identified that person. Police plan a news conference to discuss the case.

Gilbert police spokesman Sgt. Bill Balafas has said that all the evidence points to the shooting being related to domestic violence. He didn't elaborate. Officers have recovered two handguns and a shotgun.

The shootings occurred Wednesday afternoon in a subdivision filled with stucco homes with red-tile roofs.

Balafas 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 hospital.

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.

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."