BOSTON — A Boston man has pleaded not guilty to charges he was drunk behind the wheel when he struck and killed a pedestrian with a rental car and then fled the scene.

State police said 39-year-old Anthony Buchanan, of Dorchester, was driving erratically and speeding when he struck 46-year-old Johnette Sims, of Dorchester, around 10:30 p.m. Saturday at an intersection in Mattapan.

Buchanan turned himself in to police early Sunday morning and was arraigned Tuesday. A judge ordered him held on $5,000 bail and required he remain alcohol-free and stay away from the victim’s family.

His lawyer declined comment.

Suffolk County District Attorney Daniel Conley says the investigation was helped by video footage from a camera worn by someone riding a scooter nearby who was not involved in the crash.