James Jones Jr. was a sharp-dressed man, especially for a 21-year-old college student. It was common to see him wearing ties to his Clark Atlanta University classes, a friend said late Tuesday.

“He always wore suits, trying to look professional,” Terayle Hill told The Atlanta Journal-Constitution. “He was ambitious.”

But on Tuesday, Jones was being mourned on campus and by family members. He was robbed, shot and killed Monday night while attempting to buy an iPhone6 from Craigslist, Marietta police said Tuesday afternoon. Less than 24 hours later, investigators had arrested three suspects and charged them with murder.

“This has to stop,” Officer David Baldwin told the AJC. “There’s nothing on the internet for sale that’s worth your life.”

Around 9:30 p.m. Monday, a possible car crash was reported on Jamaica Cove, Baldwin said. Officers arrived to find Jones dead behind the wheel of his car.

Jones had responded to a Craigslist ad and was attempting to buy a phone when he was approached by three people, Baldwin said. There was no phone to sell.

“It was set up for them to rob whoever showed up,” Baldwin said.

Police arrested Jordan Baker, 18; Jonathon Myles, 19; and Kaylnn Ruthenberg, 21. All three were charged with felony murder, armed robbery and aggravated assault and were booked into the Cobb County jail.

Jones, a native of Daytona Beach, Fla., was a junior chemistry major at CAU, the University said in an email to students.

“Mr. Jones was a serious scholar and a kind, engaging spirit whose work and comportment spoke well of the University’s core values and those long ago instilled in him by those contributing to his upbringing,” the email said.

Jones previously played football at CAU and served as a mentor in local elementary and middle schools. Though Jones started college a year before Hill, the two were friends and had a “mutual respect for each other,” Hill said.

“He was literally just here,” Hill said.

The university plans to honor Jones later in the week.