A South Shore man accused of fatally shooting a Markham man while they were riding together in a vehicle last summer on the Dan Ryan Expressway was ordered held without bail Thursday.

Deonte Young, 26, faces a charge of first-degree murder in the death of 23-year-old Shaquille Dirkans, according to Cook County prosecutors.

Young was also charged with unlawful use of a weapon and resisting a police officer after he was seen tossing a .40-caliber handgun Wednesday when officers tried to take him into custody in Englewood, authorities said.

Late in the evening on July 27, Young and Dirkans were backseat passengers in a white Mercedes as the vehicle drove north on Interstate 94, prosecutors said.

Without provocation or warning, Young, who was distraught over the death of a friend six years earlier, pointed a gun at Dirkans and pulled the trigger, striking the 23-year-old in the neck, prosecutors said.

Deonte Young | Chicago police

The front-seat passenger wrestled the gun from Young’s hand after the shot. Young bit the passenger near his left eye during the struggle and then tried to climb into the front seat to attack the driver, prosecutor said.

The vehicle was brought to a stop on the expressway near 25th Street, according to Illinois State Police.

Young chased the driver from the vehicle while the front-seat passenger also fled and discarded the gun over the side of the I-55 on-ramp, prosecutors said. State troopers found Young laying in a grassy area about three blocks away with blood on his clothes.

Dirkens was found dead in the back seat of the Mercedes, authorities said.

State police recovered the handgun near the expressway and a spent shell casing from inside the Mercedes was matched to the weapon through forensic testing, prosecutors said.

The driver and front-seat passenger both identified Young as “the only person holding a gun” when Dirkans was shot, prosecutors said.

An arrest warrant charging Young with Dirkans’ killing was issued Nov. 29, according to court records.

On Wednesday, Chicago police officers responded to a call of a person with a gun in the 6300 block of South Racine and tried to detain Young for questioning, according to his arrest report.

Young fled the stop, but was taken into custody about a block away, police said. During the pursuit, he was seen tossing a .40-caliber Glock handgun to the ground and was also found in possession of an additional magazine loaded with live rounds.

Prosecutors said Young is a convicted felon and is not allowed to possess a gun.

Judge Sophia Atcherson ordered Young held without bail and his next court date was set for Dec. 27.