Tony Stewart, the NASCAR star who hit and killed sprint car driver Kevin Ward Jr. in a devastating accident last month, will not face criminal charges.
The decision came from a grand jury in Ontario County, N.Y. The accident happened at Canandaigua Motorsports Park on Aug. 9, when the three-time NASCAR champion, who races open-wheeled sprint cars for fun, struck Mr. Ward after he had stepped onto the track during a sprint car race.
Ontario County district attorney Michael Tantillo, citing a toxicology report, said that Ward had been under the influence of marijuana the evening of the incident "enough to impair judgment" and that videos examined by investigators showed "no aberrational driving by Tony Stewart."
After the grand jury's decision, NASCAR spokesman Brett Jewkes issued a statement.
"There are no winners in tragedy," he said. "Our thoughts and prayers remain with the Kevin Ward Jr. family and Tony Stewart as they all cope with this tragic incident at Canandaigua Motorsports Park. This has been a difficult time for everyone involved and we have respected the local authorities responsible for reviewing this case."
During the race, Mr. Stewart's car appeared to come into contact with Ward's, pushing Ward to the outside of the track. Ward's car spun out, but the cars continued to zip around the track. Then, in video footage of the accident, Ward appeared to notice Stewart's vehicle approaching and proceeded to wave his arms, stepping toward the interior of the track. Moments later, the right side of Stewart's car made contact with Ward, who was pronounced dead at a hospital.
Why Ward moved into the track remains unknown. Some said he was trying to confront Stewart, whom he may have blamed for the accident.
Controversy has ensued, and there has been anger directed at Stewart. But for the most part, there has been confusion. People have wanted to know how and why the incident happened.
"I truly don't understand how in the world it happened and exactly what went on there," Kasey Kahne, a NASCAR driver who also owns a sprint car team, told ESPN. "There's only a few people who would. There's no media person that can, and there's no fan that can. There's too much you can't see."
In the wake of the accident, Stewart stopped racing for three weeks to deal with his "sadness and pain," before returning to racing in Atlanta on Aug. 31. His return drew the ire of critics who noted that, if Stewart were charged with a crime, it would be detrimental to NASCAR. While Stewart is not the first NASCAR driver to return to racing after killing a fellow driver, he is the first to return after killing someone who was on foot.
Stewart cooperated with the investigation into the accident, but he did not testify before grand jury. In a prepared statement, he expressed deep sadness about the events that had transpired.
"This has been the toughest and most emotional experience of my life, and it will stay with me forever," Stewart said. "While much of the attention has been on me, it's important to remember a young man lost his life. Kevin Ward Jr.'s family and friends will always be in my thoughts and prayers."
While NASCAR was not involved in the race, it announced changes to its rules last month that require drivers to stay in their vehicles when accidents occur until safety workers arrive, the only exception being if they are at risk from fire.
• Material from The Associated Press was used in this report.