Police nab robbery suspect with machine pistol

Chicago police caught an armed robbery suspect carrying an automatic pistol in the South Loop just before midnight.

Officers responding to a call at a convenience store near 16th and Michigan spotted the suspect.

He fled and was caught in an alley near 18th and Wabash after a brief chase.

Police say he was carrying a Mac 11, which is like a mini-machine gun with a clip holding more than 30 bullets. 

Cash from the robbery and a small amount of marijuana were also recovered.

The arrest was made less than a block from the 1st District police station.

Charges are pending.