A teenager will be charged as an adult in the brutal robbery of an 85-year-old man outside a Brooklyn Center grocery store earlier this year, according to a criminal complaint lodged Tuesday.

A second suspect, who police believe carried out the assault on the elderly man, has not yet been charged. The teenager, who is accused of using the victim's credit card, refused to tell police the name of his alleged accomplice.

The teen, who was 16 at the time of the crime and has since turned 17, was charged with a single count of first-degree aggravated robbery and is being held in custody, authorities said. At a hearing on Monday, he was ordered by district Judge James Moore to stand trial as an adult.

The Star Tribune generally doesn't name juvenile suspects.

At about 2:15 p.m. on July 11, the victim was sitting in his car in the parking lot of the Cub Foods at 3245 County Road 10, waiting for his wife to finish shopping, the complaint said. As he was waiting, a man got into the passenger seat and started to punch him repeatedly in the face, he would later tell investigators.

"The suspect walked away for a few seconds then came back and assaulted him again," the complaint said. "The victim said his wallet was grabbed out of his pocket and the keys were taken from the ignition of his car."

The robber fled before police arrived. He was later seen arguing with the teenaged defendant outside a nearby bank, authorities said.

The other suspect, who was described as a young male in his teens who was wearing a white shirt and a necklace with a "pendant or somethign shiny on it," remains on the loose, though authorities said they have surveillance footage showing him walking into the bank shortly after the robbery.

Prosecutors said that the victim was taken to an area hospital, where he was treated for his injuries.

Investigators learned that one of the victim's credit cards was used within minutes of the robbery to rack up more than $2,500 in charges online, which led them to the defendant, the complaint read. The teen was arrested four days later at the home of friend, whose address he had the purchased items shipped to, according to the complaint.

Libor Jany • 612-673-4064 Twitter:@StribJany