TREMONT - A mace-spraying robber is on the loose and police want the public's help to find him.

Cops say a man followed a woman into the elevator of her building in Tremont on March 19 and demanded her iPhone. When she refused to give it up, police say the suspect sprayed the woman with mace and then fled.

Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.