The 22-year-old man accused of shooting and killing a Baldwin Park police officer, and another man, made his first court appearance on Wednesday and was ordered to remain jailed without bail until his July 31 arraignment.

Eduardo Roberto Medina-Berumen, who was injured in a gun battle with police during the May 31 incident, appeared at the Pomona Courthouse for his hearing in a wheelchair.

He faces two counts of first-degree murder for the deaths of 35-year-old Officer Samuel Riveros and 43-year-old Darius Wong, a Hacienda Heights man and father of two. He also is charged with two counts of attempted murder for allegedly firing at two other Baldwin Park police officers, one who was wounded by gunfire.

Wong was shot and killed as he was attempting to park his car on the street after dropping off his daughters, wife, and sister-in-law at a Baldwin Park family party Saturday evening.

Minutes later, just after 7:12 p.m., police responded to reports of a man armed with a rifle, shooting on the 4200 block of Filhurst Avenue.

Sheriff Robert Luna said earlier that as two police officers arrived, they found a man lying on the sidewalk "unresponsive, that ultimately, unfortunately, was Mr. Wong."

The two officers who arrived in separate cars, were "immediately fired upon by this suspect, who had a rifle" Luna said. "An officer-involved shooting occurred at that time and Officer (Anthony) Pimentel was injured as a result of the suspect's gunfire."

Riveros, a nine-year department veteran, arrived shortly after and was struck by gunfire, Luna said. More officers responded to the scene and a second officer-involved shooting occurred with the suspect. Medina-Berumen suffered gunshot wounds and was treated in the hospital.

An AR-15-style weapon with two high-capacity magazines was recovered at the scene, Luna said earlier. Medina-Berumen also faces a possession of an assault rifle charge.

During Wednesday's brief court hearing, Deputy District Attorney Michael Michelena told Superior Court Judge Ramiro P. Cisneros that prosecutors can prove the defendant was standing outside his home with a short-barrel rifle and "started firing indiscriminately."

Michelena said Wong was shot before officers arrived. Officers "took him (Medina-Berumen) into custody after he ran out of ammunition," the prosecutor said.