CHICAGO (CBS) — The gunman who allegedly shot and killed off-duty Chicago Police Officer John Rivera on Saturday once applied to become an officer himself, and allegedly shot “the first Hispanic man that he came in contact with” after a fight at the flagship McDonald’s restaurant in River North.

Menelik Jackson 24, and Jovan Battle 32, both have been charged with one count of first-degree murder and three counts of attempted murder. Jackson, the alleged gunman, also was charged with one count of resisting arrest for fighting with officers when he was taken into custody.

Police did not say exactly what Battle’s role was in the shooting, but said he was there when Jackson shot the victims.

“He’s complicit in what happened,” Police Supt. Eddie Johnson said.

Cook County Judge John Lyke ordered Jackson and Battle held without bail Monday afternoon, calling the shooting “one of the most senseless and evil acts I’ve heard of.”

Judge John Lyke: “This is one of the most senseless and evil acts I’ve heard of. All over a fist fight.“ https://t.co/4rWGLIj5Cb — Suzanne Le Mignot (@SuzanneLeMignot) March 25, 2019

Police said Jackson and another man got into a fight with a group of Hispanic men on a party bus at the flagship McDonald’s restaurant at 600 N. Clark St. about an hour before the shooting. Chief of Detectives Melissa Staples said Jackson was caught on video running from the McDonald’s, and coming back after the party bus had left. The other man involved in the fight was not in custody Monday morning, but police said they know who they are looking for.

Superintendent Johnson said Jackson and Battle then started searching the area for any Hispanic person they could find. He said they could face additional hate crime charges as a result.

“In an act of cowardice, Mr. Jackson went to get a gun to settle this petty dispute, which resulted in him murdering the first Hispanic man that he came in contact with,” Johnson said.

An hour later, around 3:20 a.m., Rivera, another off-duty officer, a male friend, and Rivera’s girlfriend all were leaving the Stout Barrel House & Pizza, less than a block away from the McDonald’s, and got into Rivera’s car. A short time later, Jackson and Battle walked up, and Jackson opened fire with a .40 caliber handgun, killing Rivera, and wounding a male friend in the rear passenger’s seat.

After Rivera was shot in the chin, he turned to shield his girlfriend from gunfire, and that’s when he was shot in the back.

The other off-duty officer and Rivera’s girlfriend were not injured.

Sources said Jackson fired at least 20 shots.

Another friend, Julian Martinez, said he was planning on going out with the group, but his girlfriend felt sick.

“I probably would have been in that car with them, and God knows where I would be right now; whether dead, shot, still alive or traumatized,” Martinez said.

Rivera was pronounced dead at Northwestern Memorial Hospital just before 4 a.m. Another person in the car also was wounded in the car. The other two people in the car, including a second off-duty officer, were not injured. Martinez said the other person who was shot was up and talking on Sunday, but still at the hospital.

Sources said a short time before the shooting, the suspects had approached a homeless person, asking if that person had seen any Hispanic people in the area. The homeless person directed them to Rivera’s car.

Johnson said it’s clear Jackson knew Rivera and his friends were not involved in the altercation at McDonald’s.

“He knew that those other gentlemen were on a party bus, right? They [Rivera and his friends] weren’t in a party bus. They were in a vehicle just coming out from a pizza place. So it appears that he was just looking for a Hispanic person,” Johnson said. “He settled for the first Hispanic he saw.”

Police confirmed Jackson once filled out an application to become a police officer in 2017. When the department was in the process of conducting a background check on him, Jackson was charged with an armed home invasion. He pleaded guilty, and was sentenced to 30 months probation.

“The most egregious part about him is that he actually once thought he had what it took to wear a Chicago police star,” Johnson said. “Today, he stands accused of committing the ultimate disgrace to everything that this star stands for.”

RELATED: John Rivera, 23, Off-Duty CPD Officer Fatally Shot In River North: What We Know | At Least 12 Detectives Working To Find Out Who Killed CPD Officer John Rivera

Police said the gun used in the 2017 home invasion was seized and placed in evidence, and was not the same gun Jackson used to kill Rivera.

“One of the most disgusting things about this particular incident is that this guy actually had the nerve to think that he could become a Chicago police officer. It’s disgusting,” Johnson said. “The whole situation is tragic, but when you pile that on to it, it just makes it tougher for us to deal with.”

Police said Battle was arrested near the scene of the murder not long after the shooting.

Johnson said cameras caught Jackson getting into his own car after the shooting and driving away. Officers on patrol in the 2nd District on the South Side later scanned his license plate, and tracked the car to his apartment, where he was later arrested. Staples said the clothing Jackson wore at the time of the shooting and the murder weapon were found in his apartment.

Police said Jackson was arrested using Rivera’s cuffs.

When arresting the shooter Jackson, Detectives used Ofc. Rivera's handcuffs to place him into custody. Also, we learned from those in the car that when shots were fired, Rivera leaned over and shielded his girlfriend with his body from the gunfire. pic.twitter.com/DB1AvxbFhk — Anthony Guglielmi (@AJGuglielmi) March 25, 2019

Johnson’s son, Daniel, worked alongside Rivera at the Chicago Police Department’s 6th (Gresham) District on the South Side.

“They lost a friend, and Chicago lost a young guardian who wanted nothing else but to dedicate his life to making the city that he grew up in safer,” Johnson said.

Gresham District Commander William Bradley said he’d seen Rivera the day before the shooting, when he was handling a homicide scene before ending his shift on the third watch around 10 p.m. Friday.

“He was not only a police officer, he was a son, a nephew, a cousin, but he was part of our 6th District family,” Bradley said. “He went out there every day trying to make the city safer and better; and we’re going to work to keep those officers going, and honor his memory, and support his family.”

Hegewisch barber Neko Castillo says Rivera was a friend who wouldn’t hurt a fly.

“One of those situations where some people ask, ‘oh, do you think he could have been having altercations with anybody?’ From my point of view from knowing him, I don’t think so,” Castillo said.

Colleagues, strangers and officers all stood in the rain Sunday evening as flashing blue lights led Rivera’s body on a procession from the Cook County Medical Examiner’s office to the funeral home.

Jennifer Navarro said she and 23-year-old Rivera first became friends while attending Harold Washington College. The two of them shared a lot of great times together.

“We used to love going to this karaoke bar in Chinatown called Number 18. That was our spot,” Navarro said. “When he smiled, he glowed.”

That glow is now gone.

Navarro said she was devastated when she heard about Rivera’s death Saturday morning.

“Part of my heart literally felt like it was taken away,” she said.

Police say Officer Rivera was a part of the force for 22 months. Footage from a murder scene at 84th and Sangamon Friday showcases one of the final times Rivera would wear the uniform.

The 23-year-old’s uncle is retired CPD chief of internal affairs Juan Rivera.

The rookie cop grew up in Chicago’s Hegewisch neighborhood on the city’s Far South Side.

He attended Mt. Carmel before transferring to Brother Rice where he graduated in 2013.

The school’s administration said in a statement, “We express our deepest condolences to his family. John is remembered as a nice, polite, and soft spoken young man.”

Services for Officer Rivera begin Friday with a visitation 3 to 9 p.m. at Elmwood Chapel. The following day, a funeral mass will be held at the Church of Annunciata at 10 a.m.