Stewart struck and killed 20-year-old Kevin Ward Jr. on Aug. 9 during a sprint car race at Canandaigua Motorsports Park. The local sheriff's and D.A.'s offices have been investigating the matter since then.

"Over the past several weeks, I have reviewed with members of the Ontario County Sheriff's Department their investigation, as it progressed, in the Tony Stewart matter," Tantillo said. "Recently that office concluded its work and forwarded the complete case file to me. Upon my review of all of the information contained in the entire investigation, I have made the determination that it would be appropriate to submit the evidence to a grand jury, for their determination as to what action should be taken in this matter.

"Accordingly, the evidence developed in the investigation will be presented to an Ontario County grand jury in the near future."

"Because of the confidential nature of these proceedings, I cannot state who will be called as witnesses, or what any witness's expected testimony will be," he added. "When the presentation has been completed and a determination has been made, I will advise the public and the media at that time of the results."

Stewart released the following statement following the D.A.'s announcement:

"I respect the time and effort spent by both the Ontario County District Attorney and the Sheriff's Office in investigating this tragic accident. I look forward to this process being completed, and I will continue to provide my full cooperation." ​

Stewart-Haas Racing has confirmed that Stewart will compete at this weekend's NASCAR Sprint Cup race at New Hampshire Motor Speedway this weekend.