I am not sure how much this played into the grand jury not indicting Tony Stewart, but the DA made a point to mention it when he could have left it out. Here are the details via the Charlotte Observer.
The sheriff’s office said last week it had submitted what it described as a “thorough” investigation to the district attorney’s office for review, including a recently received forensic video enhancement completed by the New York State Police laboratory in Albany, N.Y.
The sheriff’s office has been in possession of at least two videos of the incident, only one of which has been viewed by the public.
According to a handbook from the New York State Unified Court System, a grand jury can vote to indict an individual if it finds sufficient evidence that a crime has occurred to take the case to trial. Otherwise, the case can be dismissed or the grand jury can direct the prosecutor to file information accusing the person of an offense less serious than a felony.
Tantillo said Wednesday that toxicology results showed Ward was under the influence of marijuana at the time of the incident. No toxicology tests were done on Tony Stewart, Tantillo said, because in New York state law enforcement officials cannot compel the tests on a person not charged with a crime.
It is very difficult to prove intent, so even though there are a lot of people who believe Tony Stewart intentionally hit Ward, with some many conflicting accounts it was going to be hard to indict him.