Police have arrested a man accused of robbing a woman in a car parked outside a Walmart store in Riverhead earlier this month.

Christopher M. Laterza was arrested Saturday afternoon in Riverhead and charged with first-degree robbery, police said.

advertisement | advertise on newsday

Police said Laterza used a utility knife on March 2 to threaten the woman, whose pocketbook was stolen.

The robbery happened shortly before 5 p.m. at the Walmart store on Old Country Road, police said.

Laterza, whose age and hometown was not released, is being held until his arraignment.