URBANA — Witnesses in a Champaign County murder trial say they saw nothing to suggest that Marcus Brown died a violent death.

But after an autopsy on the 21-year-old man, authorities learned that he sustained a single gunshot to the back of the head that bled mostly internally.

It was the bullet in his head that was linked to Steven Monroe, 27, whose last known address was in the 600 block of East Perimeter Road, Rantoul.

Monroe's jury trial for the first-degree murder of Mr. Brown began Monday in Champaign County Circuit Court.

Mr. Brown's friend, James Stewart Jr., said he found Mr. Brown dead in his own apartment at the Bell Apartments on U.S. 136 east of Rantoul on Jan. 7. Stewart said he had called his neighbor, whom he saw daily, a couple of times earlier that day without getting through, so he went to his apartment about noon.

He found the door open and saw his friend lying on the bedroom floor with no signs of life. Thinking he had suffered an asthma attack, he did chest compressions on him but to no avail. He then removed cigars from his hand and took Mr. Brown's safe back to his apartment.

"I didn't want the police to come in and say it was just another drug dealer," and not investigate thoroughly, Stewart said of his decision to remove those items from Mr. Brown's apartment. The cigars, he explained, were to be hollowed out and repacked with marijuana.

Rantoul police, Champaign County sheriff's deputies and Chief Deputy Coroner Steve Thuney all agreed they saw nothing remarkable about Mr. Brown or his apartment to suggest he'd been murdered. The residence was sparsely furnished but neat.

Thuney said there was a small amount of blood on his gloves after he checked Mr. Brown's head for injuries. Because rigor mortis had set in and the body was cold, Thuney estimated Mr. Brown had been dead at least 12 hours. Thuney found an inhaler in Mr. Brown's front pants pocket and a wallet with his ID in his back pocket.

Thuney and sheriff's investigator Dwayne Roelfs said they saw cannabis on Mr. Brown's mattress.

Stewart said he noticed that Mr. Brown's small laptop computer was missing from the place where he always kept it open, playing music on it.

Roelfs said he checked Mr. Brown's cellphone for text messages and learned that he viewed one at 10:29 p.m. Jan. 6, but one that came at 11:03 p.m. had not been read. Roelfs also said he was present at Mr. Brown's autopsy on Jan. 8 when bullet fragments were removed from his head.

Sheriff's investigators sent those to the state crime lab, where scientists eventually matched those bullet fragments to rounds in a different shooting that happened on Heath Drive in Rantoul just before midnight on Jan. 7. Monroe was arrested for that other crime and investigators, thinking it was more than coincidence that there would be two shootings the same day in and around Rantoul, linked the bullets to the same gun.

For that other case, Monroe was charged with aggravated battery with a firearm, aggravated discharge of a firearm, reckless discharge of a firearm and unlawful possession of weapon by a felon. Evidence about that case is also being heard this week.

Ballistics experts are expected to testify to the connection and the cases should go to the jury Wednesday or Thursday.

Urbana attorney James Dedman is representing Monroe. Assistant State's Attorney Steve Ziegler is prosecuting. Judge Tom Difanis is presiding.

Also charged with Mr. Brown's murder are Roy Duckworth, 27, of Rantoul, and Joseph Emery, 33.

Duckworth is in the county jail, but Emery has not been found.