The Dallas Morning News reports 19-year-old Ethan Dorris apologized Monday and said the youths had no right to do what they did.
Dorris pleaded guilty to manslaughter in the 2009 death of Jonathan Bird of Wylie. Police say Bird was attacked with a hammer after telling some teens to stop driving so fast through a neighborhood.
Prosecutors say Travis Harmon of Celina was the driver. Harmon pleaded guilty to manslaughter and last month was sentenced to six months in jail and 10 years of deferred adjudication probation.
Three other teens are serving penalties ranging from probation to 24 years in prison.