The man who allegedly tied up two workers and robbed a St. Paul Radio Shack at gunpoint in January was charged Monday but remains at-large.

Robert Castile, 28, address unknown, was charged via warrant in Ramsey County District Court with two counts each of kidnapping and first-degree aggravated robbery.

According to the complaint: Castile entered the Radio Shack at 2026 Ford Parkway about 2 p.m. on Jan. 12 and asked to see antennas. He pointed a handgun at two employees, ordered one to put a sign on the front door indicating the store was closed and ordered the employees to place iPhones and Galaxy 4 phones into a backpack.

Castile filled three bags with cellphones and electronic items, police said. He bound the employees' hands with zip ties and then took their driver's licenses and cellphones.

The workers watched Castile on surveillance video until he left the store, at which point they freed themselves. One left the store and ran into Castile, who chased him with a handgun for 30 yards, the charges said. The employee returned to the store.

DNA evidence from one of the zip ties was traced to Castile's DNA profile stored in the National DNA Index System. He has firearm and aggravated battery convictions in Illinois.

Authorities believe he is a suspect in a similar Radio Shack robbery in Wisconsin.

GPS data from one of the stolen phones placed it in Chicago.

CHAO XIONG