Kevin Ward investigation complete

— -- The sheriff's office in Ontario Country, New York, announced Thursday that the investigation into Kevin Ward Jr.'s death is complete. 

An announcement is expected from the district attorney's office next week on what action will be taken based on the results of the investigation. 

Ward, 20, was killed when he was struck by Tony Stewart's car during an Aug. 9 sprint car event in upstate New York. Ward climbed from his car after it had spun while racing for position with Stewart, then walked onto the racing surface waving his arms in an apparent attempt to confront Stewart.

Authorities said the first car to pass Ward had to swerve to miss hitting him. The front of Stewart's car then appeared to clear Ward, but Ward was struck by the right rear tire and hurtled through the air. He died of blunt force trauma.

Since Ward's death, NASCAR has announced a rule that prohibits drivers from exiting a crashed or disabled vehicle -- unless it is on fire -- until safety personnel arrive.

Information from The Associated Press was used in this report.