Editor's note: For more on the story, visit CNN affiliate KTLA.
Los Angeles (CNN) -- Prosecutors will seek the death penalty against a 41-year-old Southern California man charged Friday with murder in this week's mass shooting at a hair salon, Orange County District Attorney Tony Rackauckas said.
Scott Evans Dekraai of Huntington Beach, California, allegedly shot his ex-wife and seven other people to death at the Salon Meritage in the small coastal community of Seal Beach, Rackauckas said Friday. A ninth person was wounded.
Prosecutors formally filed eight counts of first-degree murder and a felony count of attempted murder against Dekraai on Friday. The first-degree murder charges carry the special circumstance of multiple murder, the prosecutor said.
Dekraai and his ex-wife, Michelle Fournier, 48, were in a custody battle over their 8-year-old son, and the dispute was the motive in the shooting, Rackauckas said. The prosecutor called Dekraai "a methodical and merciless killer."
On Friday afternoon, Dekraai appeared before Orange County Judge Erick L. Larsh, who, at the request of attorneys, rescheduled Dekraai's arraignment to November 29.
Dekraai is not taking his antipsychotic medication, and his attorney asked the court to make the drugs available to Dekraai while he is being held in jail without bail.
The judge said he would order a medical team to evaluate Dekraai and, in a response to another defense request, would see if Dekraai's current wife could deliver his spinal cord implant stimulator, which is needed because of a 2007 accident Dekraai experienced.
Balding and with a salt-and-pepper goatee, Dekraai appeared calm inside the courtroom's detainee cage. One person in the gallery shouted "You coward!" Then, as he exited the courtroom, a sobbing woman uttered "I hate you! I hate you!"
Dekraai's attorney, Robert Curtis of Long Beach, told the court that he's considering a change of venue.
Earlier Friday, authorities held a press conference and recounted how Dekraai's ex-wife, a hair stylist at the salon, was working near the entrance and was among the first two people shot.
On the morning of the shooting, which occurred Wednesday, Dekraai and Fournier got into an argument about child custody, authorities said.
"We're sort of guessing. We believe that the custody battle wasn't going well for him. We don't know the contents of their conversation or anything," Rackauckas said.
Hours later, the gunfire rampage at the salon, just blocks from the ocean, unfolded around 1:20 p.m., authorities said.
"He also considered the people who were friends and who worked with his ex-wife were enablers, and he didn't have much use for them either," Rackauckas said.
He was armed with three guns -- a 9 mm Springfield, a Smith & Wesson .44 Magnum, and a Heckler & Koch .45 -- and was wearing body armor during the shooting rampage, Rackauckas said. He used at least two of those guns, the prosecutor said.
Rackauckas summarized the mass shooting, saying Dekraai "walked through the salon shooting anyone close enough to hit. He stopped to reload during this spree, and he continued gunning people down. He was not satisfied with murdering his intended target, his ex-wife. For almost two minutes, Dekraai shot victim after victim, executing people by shooting them in the head and chest.
"He shot eight people inside the salon. But he was not done. He then walked out of the salon and shot a ninth victim, a male, who was sitting nearby in a parked Range Rover. The reason for this rampage: revenge," he said.
"We believe that the defendant committed this unimaginable act of violence because he wanted to kill his ex-wife over a custody dispute concerning their 8-year-old son. He was willing to end any life in his path, and he did. Clearly this two-minute murder spree could not have been about loving his son," the prosecutor said.
While Dekraai allegedly carried out the mass murder, his son was sitting alone in the principal's office at school, waiting for his mother or father to pick him up, authorities said.
"That little boy is also a victim. He is now left to mourn the murder of his mother and grow up with the knowledge that his father (allegedly) committed a mass murder," Rackauckas said. "What sick, twisted fatherly love is this?"
In addition to Fournier of Los Alamitos, the people killed were salon employee Victoria Ann Buzzo, 54, of Laguna Beach; David Caouette, 64, of Seal Beach, who was in the vehicle outside the salon; salon employee Laura Lee Elody, 46, of Huntington Beach; salon owner Randy Lee Fannin, 62, of Murrieta; salon client Michele Daschbach Fast, 47, of Seal Beach; salon client Lucia Bernice Kondas, 65, of Huntington Beach; and salon employee Christy Lynn Wilson, 47, of Lakewood, authorities said.
Dekraai allegedly shot Caouette, who was in the parked vehicle, in the head through a closed front passenger side window, authorities said.
The ninth victim, Harriet Stretz, 73, of Los Alamitos is in critical condition. She was at the salon getting her hair done by her daughter, Laura Elody, who was among the victims.
"We do know that the victims were shot multiple times each," Rackauckas said.
About 20 people were inside the salon during the shooting, and many of them were "playing dead, hiding in backrooms, trying to get back behind things, just trying to stay out of his way," Rackauckas said.
Added Seal Beach Acting Police Chief Tim Olson: "Scott Dekraai is a coward. He armed himself with three handguns and body armor because he didn't want to be shot by police."
Police arrested Dekraai without incident as he was trying to leave the scene in a vehicle two blocks from the salon, police said. Dekraai was in possession of the three guns and "a significant amount of ammunition in his truck," prosecutors said.
In the past several months, Fournier complained to Seal Beach police about Dekraai picking up their son from school earlier than the court-ordered mandate, Olson said. That matter was forwarded to family court, and Olson said he didn't know of the complaint's disposition.
In 2007, in Long Beach, Dekraai's father-in-law applied for a temporary restraining order, but there was no follow-up, Rackauckas said.
An online search of Orange County court records shows the couple filed for divorce in 2007, with activity in the case continuing through this week. A child custody evaluator was appointed by the court in April, records show.
Fournier claimed in court papers that Dekraai was mentally unstable, had threatened to kill himself or someone else and "was almost manic when it comes to demanding absolute right to control our son," CNN affiliate KTLA said.
The couple was in court the day before the shooting, and a judge had kept custody between them equal, KTLA said.
In 1994, Dekraai filed for bankrupcy, according to court records.
The Salon Meritage is located on the Pacific Coast Highway in Seal Beach, which residents describe as a small and "fairly intimate" coastal town.
"We have multiple years with zero homicides, so this obviously is an unusual and tragic circumstance," Seal Beach police Sgt. Steve Bowles said.
The shooting is the deadliest in Orange County history, KTLA said. In 1976, Edward Charles Allaway shot nine people, killing seven, at California State University Fullerton.
CNN's Traci Tamura, Gabriel Ramirez, Ashley Hayes and Carey Bodenheimer contributed to this report.