INDIANAPOLIS -- Police on Tuesday arrested two teenagers in connection with Monday's slaying of a longtime Kroger employee, including the person investigators believe fired the fatal shot, authorities said.

David Kist, 18, was arrested at his father's Avon home Tuesday afternoon on suspicion of firing the shot that killed Wendall Anderson outside an Indianapolis Kroger store, police said.

Earlier Tuesday, police arrested Nathaniel W. Osborne, 17, who police said had driven Kist and another teen to the store, located at Kentucky Avenue and Mann Road. Authorities also said they believe Osborne hid the gun that was used to kill Anderson.

Police said the arrests were made after Osborne's other passenger -- a 16-year-old boy -- told his parents what happened and came forward with an attorney Tuesday.

The 16-year-old was not charged in the case Tuesday, 6News' Rick Hightower reported.

Police said Kist confessed to shooting Anderson after his arrest. Kist told investigators that he was trying to rob Anderson, according to police.

Kist was being held on preliminary charges of murder and attempted robbery.

Osborne and the 16-year-old told investigators they thought they were going to the store to buy something rather than rob someone, police said.

Police said that after they interviewed Osborne, they found the gun they believe was used in the shooting.

Anderson, 58, was shot once in the chest as he arrived at work at about 5 a.m. Monday, police said. He was taken to Wishard Memorial Hospital, where he died less than two hours after the shooting.

Anderson had worked for Kroger for 39 years.