More than 100 law enforcement officers from across Northern California responded without being asked after hearing that one of their own had been killed at the start of a shooting rampage, a sheriff's spokeswoman said Saturday.
Federal, state and local officers eventually swarmed six separate crime scenes across a 30-mile region encompassing two counties, Placer County sheriff's spokeswoman Dena Erwin said.
"It was an amazing response," Erwin said. "We don't call for those people, they just show up on their own because they know a fellow officer has been shot."
The officers from the state Department of Justice, FBI, U.S. Department of Homeland Security and other agencies will be questioned as part of the complex investigation into the attack on Friday that ended after two deputies were dead and two other victims were wounded.
Placer County Sheriff Ed Bonner described the crime scenes as "incredibly chaotic" and vowed to piece together details of the attacks.
"It's a very large scale investigation for sure," Erwin said. "It's just a nightmare."
Two suspects were questioned for hours as authorities sought a motive for the shootings that began when Sacramento County sheriff's Deputy Danny Oliver, 47, was shot in the forehead with an assault rifle at close range as he checked out a suspicious car in a motel parking lot.
Police suspect the shooter was 34-year-old Marcelo Marquez of Salt Lake City, who was being held on suspicion of two counts of murder, two counts of attempted murder and two counts of carjacking.
A woman with him, 38-year-old Janelle Marquez Monroy, was in custody on suspicion of attempted murder and two counts of carjacking.
Jail records contained no indications that either suspect had outstanding arrest warrants.
Both were being held without bail. Initial court appearances were expected Tuesday.
Neither immediately responded to emails sent through the jail requesting comment. No attorneys were listed for either suspect.
Oliver, a 15-year veteran of the department, was the first Sacramento County deputy killed since 2008. He left a wife and two daughters.
After Oliver was shot, his partner fired at the attackers, who drove about a mile before attempting a carjacking.
Driver Anthony Holmes, 38, of Sacramento was shot at least twice, including once in the head, sheriff's spokeswoman Sgt. Lisa Bowman said. A nursing supervisor at UC Davis Medical Center said Saturday that Holmes had been upgraded from critical to fair condition.
The attackers then stole a red Ford pickup from a gardener and fled to the Sierra Nevada foothills city of Auburn in neighboring Placer County, about 30 miles northeast of Sacramento.
Two deputies who approached the pickup while it was parked alongside a road were shot with an AR-15-type assault weapon, Placer County sheriff's spokeswoman Dena Erwin said.
Homicide Detective Michael David Davis Jr., 42, died at a hospital 26 years to the day after his father, for whom he was named, died in the line of duty as a Riverside County deputy.
Michael David Davis Jr. was a father of four and also had spent 15-year with his department.
The wounded deputy, Jeff Davis, a 17-year department veteran, was treated for a gunshot wound in the arm. The two deputies were not related.
Monroy was arrested at the scene of those shootings with a handgun in her purse, Erwin said. Deputies finally used tear gas to flush Marquez from the basement of the home where he hid for several hours.
Residents nearby were told to stay indoors, and schools were locked down during the search.
A search of Utah court records for Marquez shows a history of about 10 tickets and misdemeanor traffic offenses between 2003 and 2009. Those records list one speeding ticket for Monroy in 2009 and three small claims filings attempting to collect outstanding debts.
Two phone numbers listed for suspects were both disconnected.
Flags at the state Capitol were ordered flown at half-staff and Gov. Jerry Brown issued a statement extending his sympathy to the families of the slain officers.
The slaying of the deputies was the single deadliest day for California law enforcement since February 2013. In separate incidents that month, former Los Angeles police officer Christopher Dorner killed two law enforcement officers, and two Santa Cruz police detectives were shot and killed.