LOS ANGELES (AP) — Prosecutors on Monday filed a murder charge against a man suspected of killing a good Samaritan who tried to detain him after an attempted carjacking and burglary near Los Angeles last week.

Joey Casias was among several residents of Covina who confronted a man who police said broke into a parked BMW and then tried to carjack another vehicle on Dec. 21.

When the carjacker tried to attack another man, Casias tried to stop him and was shot and killed, investigators said.

Police arrested Trevor Howard Thompson, 34, after an hourslong standoff.

In addition to murder, Thompson faces charges including attempted murder, assault, burglary and attempted carjacking, the Los Angeles County District Attorney’s Office said in a statement.

It wasn’t known Monday if Thompson has an attorney.

“This is an especially heartbreaking incident since Mr. Casias was simply acting as a good Samaritan,” District Attorney George Gascón said.