JOLIET – A 21-year-old man will spend at least 13 years behind bars for firing an assault rifle at a clerk during a robbery at a Joliet gas station.

Devonte C. Jessup, of Joliet, pleaded guilty Wednesday to armed robbery in exchange for a 30-year sentence. Jessup will first be eligible for parole after serving half his sentence and will receive credit for the year-and-a-half he's spent in the Will County jail.

"I want to apologize for the crime I committed. My intent was never to hurt anybody. The gun went off by accident," Jessup told Judge Daniel Kennedy.

About 11:35 p.m. July 25, 2014, Jessup came into Citgo, 609 Ruby St., wearing a "red hooded sweatshirt with a black bandana over his face and carrying an AK-47 rifle," Will County assistant state's attorney Fred Harvey said.

Jessup demanded the clerk put money from the register on the counter, which was taken by his accomplice, Farleigh O. Jones, 21, of Joliet. Jones pleaded guilty to armed robbery in exchange for a 16-year sentence.

Jessup then demanded more money, but when the clerk said he was unable to open the safe, Jessup shot a round into the wall behind the clerk and fled, Harvey said.

Patrol officers reportedly found Jessup near Oakland Avenue and Moran Street, two blocks north of the gas station, and Jones in nearby St. John's Cemetery with the AK-47 and $200.

The robbery was recorded by surveillance cameras and Jessup made a full confession to police after his arrest, according to court records.