A Pennsylvania man is about to find out how much time he'll serve for his role in a rock-throwing incident last year that badly injured an Ohio teacher traveling on Interstate 80.

Union County court officials said 19-year-old Brett Lahr will learn Tuesday how long he'll be incarcerated for the attack that left Sharon Budd with severe head injuries.

Brett Lahr pleaded no contest to a conspiracy count in March and opted to begin serving time before sentencing.

The defense lawyer for Lahr's 18-year-old brother Dylan Lahr says he plans to plead guilty to an unspecified charge during a separate proceeding Tuesday.

Union County District Attorney Pete Johnson says there may also be developments regarding the two other defendants, 18-year-old Keefer McGee and 18-year-old Tyler Porter.