POMONA, Calif. – The 15-hour standoff between a man suspected of shooting two police officers and SWAT in Ponoma, California has ended with the suspect in custody, Los Angeles County Sheriff Jim McDonnell said Saturday. One of the two officers shot while responding to the barricaded suspect died earlier Saturday.

Los Angeles County Sheriff Jim McDonnell confirmed the arrest in a news conference, CBS Los Angeles reports.The standoff ended sometime before 2 p.m.

Police identified the suspect late Saturday as Isaias De Jesus Valencia, 39, of Ponoma. Police said he is being charged with murder of a police officer and the attempted murder of other peace officers and will be held without bail.

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The motive remained unclear.

Earlier Saturday, Pomona police Chief Michael Olivieri announced the tragic news early Saturday morning, while a standoff with the suspect continues, according to CBS Los Angeles.

"It is with a heavy heart that I must report that one officer did not survive," Olivieri said in a Tweet.

It is with a heavy heart that I must report that one officer did not survive. The second officer is in stable condition. — Chief Michael Olivieri (@olivieri_ppd) March 10, 2018

The Los Angeles County Coroners office later identified the deceased officer as Officer Gregory Casillas, 30. of Upland.

The other wounded officer was shot in the jaw and is in serious condition after undergoing surgery, a law enforcement source told CBS Los Angeles.

The suspect has not been positively identified, LASD Homicide Capt. Christopher Bergner disclosed at a Saturday morning news briefing.

"We still don't have a positive ID on him," Bergner said. "We're still trying to find out where he's from, the reason that he ran. We don't have him in custody yet."

A Los Angeles County Sheriff's SWAT team was surrounding the complex in the 1400 block of South Palomares Street, where the gunman was still believed to be barricaded inside an apartment.

The standoff was ongoing as of 11:30 a.m.

Bergner said the incident began at 9:04 p.m. Friday when Pomona police were dispatched to a reckless vehicle.

The driver of the vehicle refused to stop, and a chase ensued, culminating in a traffic collision, Bergner said. The suspect then jumped out of the vehicle and ran, prompting a foot chase.

The suspect ran into the apartment complex, entered an apartment and barricaded himself in a bedroom. When the officers tried to make contact with him, he opened fire.

"As he barricaded himself in a bedroom, officers attempted to contact him, and he began firing through the door, striking two officers," Bergner said.

Los Angeles County firefighters rushed the two officers to Pomona Valley Hospital Medical Center, where one of them died. The other is expected to survive after undergoing surgery, Bergner disclosed.

LASD SWAT and crisis negotiators had spent the night trying to negotiate with the suspect to surrender. The apartment complex has been completely evacuated. Several flashbangs were set off and officers were also using a bullhorn.

Neighbors told CBS Los Angeles that the suspect lives in the building.

Meanwhile, at around 6 a.m. Saturday, police escorted the body of the slain officer to the L.A. County Coroner's Office in a procession of squad cars