Police say Sharod Johnson, 18, shot and killed Mohammed Abdel-Hamid inside the M&M Food Mart on the corner of 7th and Ann Streets in December. Abdel-Hamid was co-owner of the store.
Detectives identified Johnson as the killer using surveillance tapes from inside the store.
Johnson was arrested in Brooklyn, New York Tuesday night.
At a news conference Wednesday afternoon, Police Chief Ralph Evangelous described Johnson as a killer.
"He's a brutal cold-blooded murderer. I can say that without any thought process at all, because I watched it. I watched it on the video tape."
Abdel-Hamid's family attended the news conference. They say they are thankful the suspected killer is in custody.
Reported by Kacey Gaumer