Before a suspect in the shooting of a California officer was accused of murder, before he barricaded himself in an apartment in a deadly overnight standoff, he was an alleged reckless driver.

The suspect, Isaias De Jesus Valencia, was charged with murder Saturday after he was arrested following a 15-hour overnight standoff at an apartment complex in Pomona.

Officer Greggory Casillas, 30, was fatally shot in the incident that started Friday night. A second officer was hospitalized in serious condition, shot in the face while he tried to rescue Casillas, authorities said.

Valencia, 39, was also charged with attempted murder, the Los Angeles County Sheriff’s Department said.

“Gregg is a hero, a man to be looked up to,” Police Chief Michael Olivieri said. “He left his family at home to protect yours and his ultimate sacrifice will never be forgotten.”

Overnight standoff

The incident began Friday night when Pomona officers responded to a report of a reckless vehicle, said the Los Angeles County Sheriff’s Department, which was assisting the Pomona Police Department.

Pomona, which has a population of about 150,000 people, is 30 miles east of Los Angeles.

“When officers arrived, they located the suspect’s vehicle and attempted to conduct a traffic stop,” the Sheriff’s Department said.

“However, the suspect failed to yield, and a vehicle pursuit ensued.”

Valencia’s vehicle crashed into a parked car, and he allegedly fled on foot, leading officers on a pursuit.

“The suspect ran into an apartment complex and the officers gave chase,” sheriff’s Capt. Christopher Bergner said. “As he barricaded himself in a bedroom, officers attempted to contact him. He then began firing through the door, striking the two officers.”

He allegedly opened fire on the officers about 9:10 p.m., hours before he was detained.

During the standoff, officers made several verbal attempts to persuade the suspect to surrender, authorities said.

Law enforcement personnel and firefighters escorted Casillas’ body to the coroner’s office while the barricade situation continued, CNN affiliate KABC reported.

Fifteen hours after the standoff started, Valencia was led away in his underwear, flanked by law enforcement officials.

Rookie officer, father of two

Casillas was a rookie still in field training. He joined the department in 2014, and worked at several jobs before becoming an officer.

Law enforcement members honor the fallen officer as the coroner's van pulls away.

Law enforcement members honor the fallen officer as the coroner’s van pulls away.

In a Facebook post last September, the police chief welcomed Casillas as the “newest Pomona police officer,” saying he had just graduated from a local sheriff’s department academy class.

After Casillas’ death, colleagues expressed gratitude for the widespread condolences.

“We are deeply moved by the love and support we have received from our law enforcement brothers and sisters, our community and people across the US during this difficult time,” the Pomona Police Department said. “Our hearts are heavy as we mourn the loss of our brother.”

Casillas leaves behind a wife and two children, Olivieri said.

Valencia is being held without bail, KABC reported.

So far this year, 17 law enforcement officers across the US have died in shootings, including an officer killed Tuesday in Missouri. Officer Christopher Ryan Morton, 30, was killed after being dispatched to the wrong house, the Missouri Highway Patrol said.

CNN’s Shawn Nottingham, Marlena Baldacci and Nicole Chavez contributed to this report.