WATCH: California sheriff hammers 'sanctuary' policies after illegal immigrant charged in officer slaying

Sheriff Adam Christianson of Stanislaus County in California believes if it weren't for California's controversial "sanctuary state" law, then deputy Ronil Singh, who was murdered by an illegal immigrant on Wednesday, would still be alive.

Singh's killer — Gustavo Perez Arriaga, who authorities say is an illegal immigrant and has been previously deported from the U.S. — was arrested Friday without incident.

In total, seven individuals have been arrested in connection to Singh's slaying.

What did Christianson say?

According to Christianson, it was California's recently enacted "sanctuary" law, which essentially prohibits local law enforcement from cooperating with federal immigration authorities, that aided Arriaga in the brutal killing.

"This is a criminal illegal alien with prior criminal activity that should have been reported to ICE. We were prohibited, law enforcement was prohibited, because of sanctuary laws, and that led to the encounter with Officer Singh," Christianson said at a press conference, according to ABC News.

"Ron — an immigrant immigrated here lawfully and legally to pursue his American dream — he achieved that goal, then his dream was taken from him," Christianson said. "No, we shouldn't politicize it but we have to have a conversation about restrictive legislation that puts our communities at risk."

The motive for the crime is not yet clear. Police said Arriaga was alone when he allegedly killed Singh. After the slaying, Arriaga reportedly tried to flee to Mexico.

Anything else?

In an appearance on Fox News, Christianson continued to warn about the dangers "sanctuary" laws introduce.

"Illegal immigration doesn't serve our communities, especially criminals who victimize and exploit our communities," he said. "You can't provide sanctuary for criminals. All that does is silence the voices of our victims."

Stanislaus County Sheriff Adam Christianson on the murder of Officer Ronil Singh by an illegal immigrant: “Whether you hate the president or love the president, border security goes hand in hand with national security, the safety of our communities, and public safety" pic.twitter.com/fOICTAgBEM
— Ryan Saavedra (@RealSaavedra) December 29, 2018