On the Day after Christmas, An illegal immigrant, Gustavo Perez Arriaga, alias Paulo Virgen Mendoza, 32, a Mexican national, shot and killed police officer from Stanislaus County, California, complaint alleges

Man suspected of killing California police officer Ronil charged with murder

The man accused of shooting and killing a Northern California police officer the day after Christmas has been charged with murder, according to court documents.

The criminal complaint filed in Stanislaus County for suspect Gustavo Perez Arriaga, 32, a Mexican national, alleges that Arriaga "should have known" that Police Cpl. Ronil Singh was a "sworn police officer acting in the performance of his duties" and therefore "acted intentionally, deliberately and with premeditation."

(MORE: Suspected killer of California officer Ronil Singh had 7 alleged accomplices: Officials)

Singh, 33, was killed on Dec. 26 just before 1 a.m. after he pulled Ariaga over in his a gray Dodge Ram pickup truck because he believed he was under the influence of alcohol, authorities said.

Arriaga, an undocumented immigrant, was arrested Friday and placed in Singh's handcuffs after law enforcement surrounded a home in Bakersfield, California, about 200 miles south of Stanislaus County. He had tried to flee to Mexico after the shooting, Stanislaus County Sheriff Adam Christianson said after his arrest.

During his arraignment Wednesday, Arriaga told the judge that his real name is Paulo Virgen Mendoza and that Gustavo Perez Arriaga is just one of his aliases, ABC San Francisco station KGO reported. At least three aliases were listed on Arriaga's criminal complaint, and authorities have said that he also used several different names on social media. Authorities also say that he has known gang affiliations.

(MORE: 'We will bring him to justice': Police identify suspect in killing of California officer as Trump tweets on alleged gunman's immigration status)

Arriaga did not enter a plea during the hearing, and his attorney questioned his mental competency, according to KGO. The case has been suspended until he receives a mental health evaluation.

Seven people, including two of Arriaga's brothers, a woman described as his girlfriend and one of his coworkers, have been arrested for either misleading authorities about his whereabouts or aiding him in evading capture.