Scott Evans Dekraai, who's accused of killing his ex-wife and seven others in a shooting spree at a Seal Beach beauty salon, is expected to be charged with murder when the charges are filed Friday, the Los Angeles Times reported.

Dekraai, of Huntington Beach, Calif., is the suspect in the worst mass killing in Orange County. He was arrested Thursday morning, about a half-mile from the site of the shooting. On Wednesday, Dekraai , who turns 42 on Monday, was being held without bail after the shooting at Salon Meritage on Pacific Coast Highway.

They had him by the shirt, and when they pulled the shirt up, they realized he had a bulletproof vest, Tom Windham, a resident who witnessed the arrest, told ABC News. They took that off, and by that time they already had him handcuffed.

Orange County District Attorney Tony Rackauckas and Seal Beach Police Department Capt. Tim Olson, the department's acting chief, is expected to hold a news conference late Friday to discuss the charges.

The eight people killed were the salon's owner, Randy Lee Fannin, 62; Victoria Ann Buzzo, 54; Lucia Bernice Kondas, 65; Laura Lee Elody, 46; Christy Lynn Wilson, 47; hair stylist Michelle Marie Fournier, 48, Dekraai's ex-wife; Michele Daschbach Fast, 47; and David Caouette, 64.

The sole survivor of the shooting, Hattie Stretz, 73, remained in critical condition at Long Beach Memorial Medical Center.

He shot his wife, Cindy, a woman who was getting her hair done by the owner of the salon, Randy Fannin, told the local KNX radio station. Then he pointed the gun at Randy. Then Randy turned around, and then the man shot Randy, and then I ran.

Dekraai and Fournier had been engaged in a bitter custody battle over their 8-year-old son, neighbors said. Cindy said Fournier had taken out a restraining order against Dekraai.

There may be something to the motive as to a relationship with somebody in the salon. That is our assumption, Seal Beach Police Sgt. Steve Bowles told The Associated Press. He declined to elaborate.

The shooting shocked the residents of Seal Beach, a town about 30 miles south of Los Angeles, which is known for being very safe.

We don't experience these things, said Bowles.