LOS ANGELES_The two officers ran into a Pomona apartment building after a pursuit, chasing a suspect who had just crashed nearby and was holed up in one of the units.
As they approached, gunfire blasted through a door.
Officer Greggory Casillas, a 25-year-old Upland father just six months on the job, was struck and killed. A second officer was shot in the face trying to save him.
The Friday night shooting led to an overnight standoff that ended about 15 hours later when the suspect, identified by neighbors as Isaias Valencia, was handcuffed and taken into custody by Los Angeles County sheriff's deputies.
"It's a sad day for our community and a sad day for law enforcement in general," Pomona Police Chief Michael Olivieri told reporters, calling the fallen officer a hero. "He left his family at home to protect yours and his ultimate sacrifice will never be forgotten."
Casillas joined the Pomona Police Department in 2014. He took on different positions _ he was a records specialist and jailer before becoming a police recruit _ to "better prepare himself to achieve his goal" of becoming an officer.
He was sworn in as a police officer in September. Casillas was nearly finished with his field training when he was killed.
Raised in Los Angeles County, Casillas attended "local colleges and universities," Olivieri said. He is survived by his wife and two children, as well as his parents and two brothers.
At the end of the news conference, sheriff's deputies surrounded Olivieri as he walked away from the crowd. Some patted him on the back.
"It has been a long night," said Los Angeles County Sheriff Jim McDonnell.
As night time approached Saturday under steady rain, a few dozen people gathered at the police headquarters for a candlelight vigil. Bouquets of roses with notes of condolences covered a water fountain near the entrance.
Pomona pastors led the group in a prayer for police and the family of Casillas.
"In the midst of all of the good lord it now feels like a step back _ a setback. We have stood here too many times," said Pastor Rick DeBruyne of Lincoln Avenue Community Church, citing the years when other Pomona officers were slain: 1996, 2004, 2014.
According to an acquaintance, the suspected shooter suffers from depression and drug addiction, with a criminal background that includes a felony conviction. Valencia served in the U.S. Army and has two children, said Amos Young, who knew the suspect through his father's Pomona church, Kingdom of God Revelation Ministries.
Despite having a home, Valencia often slept on the streets and rejected help from his family, Young said.
Police said the incident began Friday night after they received a call about a reckless driver. The suspect refused to stop, leading police on a pursuit that ended when he crashed into a parked car. The driver then ran into an apartment building.
About 9:10 p.m., dispatchers relayed reports of an officer down. A law enforcement source said about 75 officers from several agencies swarmed the scene but were unable at first to move the wounded officers to safety because of gunfire.
A mother and daughter, who gave only their first names, said they ran out of their apartment after hearing the crash. Marlene, 12, said she saw the suspect exit a truck with a gun tucked under his arm and run into the nearby apartment.
When the gunfire began, Marlene began recording on her cellphone. The video shows Marlene and her mother, Jessica, 29, running for safety as the gunfire continued.
"He's inside," a woman says in the video. "Let's go!"
Marlene said she saw police bring a wounded officer outside and rip off his vest. In the video, an officer is seen giving chest compressions to an officer on the ground. Several officers huddle around them.
Marlene and other neighbors said they spotted a woman they said was the suspect's mother crying and vomiting outside the apartment building before she got into a police SUV.
Ninfa Martinez, who lives in a neighboring complex, said she saw residents running out of the building where the shooting occurred.
"Then I heard some shots and went back running," said Martinez, 24. "It was crazy."
Once the gunfire stopped, Martinez's mother and other neighbors offered coffee to residents who had fled the building, she said. Some of the displaced residents slept in their cars.
After dawn, Casillas' body was escorted by a police procession from Pomona Valley Hospital Medical Center to the coroner's office. More than a dozen law enforcement officers blocked the street in front of the apartment building where the suspect was still barricaded.
A handful of SWAT officers gathered outside the entrance. Every so often, their muffled megaphone calls to the man to come out echoed through the street.
Neighbors, some wrapped in blankets or wearing hooded jackets, watched the scene unfold from behind police tape. A few stood on top of their cars in the rain for a better view when a flash-bang device detonated about 10 a.m. An officer then again ordered the man to exit through the front door.
"Come outside with your hands up," the officer said. "Come on out."
The man was apprehended hours later, escorted to a waiting patrol car wearing underwear and handcuffs.
The shooting sparked an outpouring of support from local law enforcement.
"Another hero gone too soon. These tragedies are occurring too often, and the pains of sacrifice will never be forgotten," said Los Angeles Police Department Chief Charlie Beck.
Casillas' body was escorted by a police procession Saturday morning as it was transferred from Pomona Valley Hospital Medical Center to the coroner's office.
The last law enforcement officer killed in the line of duty in Southern California died a little more than a year ago.
Whittier Police Officer Keith Boyer was fatally shot while investigating a traffic crash in February 2017.
Michael C. Mejia, 27, a convicted felon with a history of drug possession and violent criminal activity, is accused of killing his cousin and stealing his car in East Los Angeles before crashing into two other vehicles at a Whittier intersection.
When Boyer, 53, and his partner, Patrick Hazell, arrived at the scene and ordered Mejia out of his car, he opened fire on them, prosecutors said. Boyer died and Hazell was wounded.
