SOUTH SALT LAKE — A man police say robbed a market here at knifepoint was arrested Monday after being followed by a witness with a cell phone.

At about 2:45 p.m., the 28-year-old man walked into La Guadalupana Market, 261 E. 3300 South, where he threatened a female clerk with a knife and demanded cash, according to a statement from South Salt Lake police.

The man left the market and walked into a nearby movie theater, police said, where he discarded his coat and knife.

A witness to the robbery followed the man at a distance and alerted police of his location. When he walked outside, police arrested the suspect at a bus stop on State Street. He is being held on suspicion of aggravated robbery.