Two Santa Cruz police detectives were fatally shot when they tried to question a man over a report of an alleged sexual assault, according to reports.
The man later died as well, sheriff's officials say.
Sgt. Loren Butch Baker, who was married and the father of two daughters, and Detective Elizabeth Butler, who also had two sons, were shot and killed.
The fatal and tragic altercation took place Tuesday at the California home of a man they sought to question, 35-year-old barista Jeremy Goulet.
He allegedly made inappropriate sexual advances on a co-worker at her home, authorities said. Goulet was arrested Friday, and fired the next day.
Baker, a 28-year veteran of the force, and Butler, a 10-year veteran, went to the house where Goulet was living to follow up on the case, authorities said.
They were fired upon and called for backup, and responding officers found Goulet, who died in the gunfire that followed, the sheriff's office said.
"There aren't words to describe this horrific tragedy," said Police Chief Kevin Vogel. "This is the darkest day in the history of the Santa Cruz police."
The police shootings prompted the lockdown of two schools and an automatic police call to nearby residents, warning them to stay locked inside.
The ordinarily quiet residential neighborhood echoed with a brief barrage of gunfire that killed the suspect about a half hour after the officers were shot.
A store clerk said the barrage of gunfire was "terrifying."
"We ducked. We have big desks so under the desks we went," said the clerk, who spoke on condition of anonymity and asked that her store not be identified.
After the shootings, police went door-to-door searching homes, garages, even closets, to determine whether there might be additional suspects.
Law enforcement officers filled intersections, and helicopters and light aircraft patrolled the neighborhood about a mile from downtown Santa Cruz.
The city's mayor, Hilary Bryant, was "heartbroken at the loss of two of our finest police officers who were killed in the line of duty, protecting the community we love."
"This is an exceptionally shocking and sad day for Santa Cruz."