State Police are investigating a robbery that occurred in the parking lot of the Christiana Mall on Tuesday evening just before 7.  Police say a black man demanded cash at gunpoint from a 22 year old man in the area between the DART bus stop and the food court.  The victim handed over his wallet and the suspect left in a pickup truck.  The suspect is about 23 years old, about 6’ 1” with a thin build and wore a grey hoodie and jeans.  If you have information – call Crime Stoppers.