CHICAGO (CBS) — A month after his father was shot and killed while working as a security guard at a south suburban railyard, 5-year-old Tyrone Hardin Jr. joined Harvey police as an honorary officer.

Tyrone was sworn in as an honorary officer at the Harvey police station on Wednesday.

READ MORE: Jordan Hassell Charged With Making Multiple Social Media Threats Targeting Chicago Public Schools

“Officer Hardin will be placed in the patrol division, and go on active duty,” Harvey Police Chief Denard Eaves said.

Tyrone was a little at a loss for words when they pulled a chair up to the podium so he could see over it, but his mother, Gwinette, said that wasn’t the case Tuesday night after finding out he was being made an officer.

“He’s been telling his siblings that if they do anything to him, he will lock them up,” she said.

Gwinette said Tyrone was so excited he couldn’t sleep Tuesday night.

“He’s already expressed that he can’t be put on punishment when he’s on duty,” she said.

READ MORE: MISSING: Cherish Taylor, 13, Last Seen In Auburn Gresham

Eaves said police planned to have Tyrone help them with a traffic stop while on patrol.

“There’s one area in particular where, hopefully, we can get somebody speeding,” he said.

Tyrone’s father, a security guard who worked at the Canadian National Railroad yard in Harvey, was shot and killed last month while on the job.

“We are missing a vital person, but everybody kind of helped ease it a little bit,” Gwinette said.

Tyrone Hardin Sr., 38, was working security at the railyard on Nov. 26, when a man who had allegedly stolen a woman’s car crashed near 159th and Park in Harvey and ran into the railyard to get away. The suspect allegedly shot Hardin in the abdomen before stealing Hardin’s truck.

MORE NEWS: Workers At El Milagro Locked Out After Walkout Claiming Dangerous Conditions

The suspect, 24-year-old Rashad Williams, was arrested on Dec. 4, three days after a warrant was issued for his arrest. Williams is being held without bail at Cook County Jail, charged with first-degree murder, attempted murder, and vehicular hijacking.