His attorney told Judge Eldon Fox that the "Prison Break" star "feels a deep sense of responsibility on this matter and the real issue is what level of culpability there is," but that his client wouldn't plead not guilty to the charge "because it makes it sound like he is just denying all responsibility," TMZ reported.
Bail was set at $100,000. Garrison is to refrain from driving, drinking alcoholic beverages or having contact with any victims or witnesses.
Formal arraignment will be April 11.
Garrison, 26, faces up to six years in prison if convicted on the felony vehicular manslaughter and three other charges in the Dec. 2 accident that left a 17-year-old boy dead and two 15-year-old girls injured.
Garrison allegedly consumed several shots of vodka and snorted cocaine at a party and then left with the teens in his SUV, driving it into a tree. His blood alcohol level was 0.20 and he had cocaine in his system, police said.