MARIETTA, Ga. (AP) — Clark Atlanta University says the killing of a junior chemistry major is a "devastating" loss for the school.

Police in suburban Atlanta say three people have been arrested in the death of 21-year-old James Jones Jr., who was looking to buy an iPhone from a seller on Craigslist.

Marietta Police spokesman David Baldwin says Jones was robbed and fatally shot Monday night after responding to an ad for an iPhone 6.

Baldwin says 18-year-old Jordan Baker, 19-year-old Jonathon Myles and 21-year-old Kaylnn Ruthenberg are jailed on felony murder, aggravated assault and armed robbery charges.

Clark Atlanta said in an email to students that it's reaching out to family and friends of Jones, who was a native of Daytona Beach, Florida, before finalizing any memorial tributes.