The man accused of ramming a motorcycle earlier this week and killing a recent Georgia Tech graduate was arrested previously for DUI, authorities say.

Atlanta police have arrested Darrin Murphy, 42, who was driving the car that struck motorcyclist Liam Rattray near the Vortex restaurant around 9:40 p.m. Monday night.

Murphy, who was being held without bond Wednesday,  has been charged with first-degree homicide, following too closely and driving under the influence.

Rattray was riding his motorcycle on Moreland Avenue in the Little 5 Points neighborhood when he was hit from the rear, thrown from the bike and struck by a vehicle that was going southbound. He was taken to Grady Memorial Hospital, where he later died.

Authorities say Murphy, who lives in Buckhead,  was arrested previously in October 2009 in Atlanta and charged with DUI. The charge, however, was later reduced to reckless driving.

Rattray had just graduated with a degree in public policy from Georgia Tech. Born in London, he became an American citizen three months ago.