CANANDAIGUA, N.Y. (AP) — After more than six weeks in limbo, NASCAR star Tony Stewart finally got the news he had been hoping for.

A grand jury that heard testimony from more than two dozen witnesses, including accident reconstruction experts and drivers, and looked at photographs and video decided against bringing criminal charges against Stewart for the death of 20-year-old sprint car driver Kevin Ward Jr. during an Aug. 9 race.

That doesn't mean it's over.

A few hours after Ontario County District Attorney Michael Tantillo announced the grand jury's decision in this upstate New York hamlet, the Ward family indicated in a statement read over the telephone by sister Kayla Herring that they will seek civil damages in the young driver's death.

"Our son got out of his car during caution when the race was suspended. All the other vehicles were reducing speed and not accelerating except for Stewart, who intentionally tried to intimidate Kevin by accelerating and sliding his car toward him, causing the tragedy," the family said Wednesday. "The focus should be on the actions of Mr. Stewart. This matter is not at rest and we will pursue all remedies in fairness to Kevin."

The family might have a difficult task: Tantillo disclosed that Ward was under the influence of marijuana the night he died and said two different videos were enhanced, frames were isolated and viewed at at least three different speeds and finally overlaid with grids and data. Both showed Stewart had done nothing wrong.

"The videos did not demonstrate any aberrational driving by Tony Stewart until the point of impact with Kevin Ward, at which point his vehicle veered to the right up the track as a result of the collision. Prior to that, his course was pretty straight," said Tantillo. He added that toxicology evidence from Ward's autopsy "indicates that at the time of operation he was under the influence of marijuana. The levels determined were enough to impair judgment."

Stewart's reaction was not one of celebration, and his statement had the same twinge of sadness that he's carried since he returned to NASCAR three weeks ago following three weeks of seclusion after Ward's death.

The 43-year-old NASCAR superstar acknowledged the investigation was "long and emotionally difficult" but noted it allowed time for all the facts to be presented.

"This has been the toughest and most emotional experience of my life, and it will stay with me forever. I'm very grateful for all the support I've received and continue to receive," he 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."

David Weinstein, a former state and federal prosecutor in Miami who is not involved in the case, said the toxicology evidence will make it difficult for the Wards to win a lawsuit against Stewart. He said the Ward statement showed the family was "clearly upset and at a vulnerable point."

"Hopefully, someone will explain to them that Kevin will be dragged through the mud during a civil trial," he said. "After the results of the toxicology report and the findings of the grand jury, the deep pockets will not be willing to settle this lawsuit so quickly."

The decision came nearly seven weeks after Stewart's car struck and killed Ward, sending shock waves through the top racing series in the United States. The brash and popular NASCAR driver known as "Smoke" skipped three races as he grieved, and returned to racing in late August. One of the biggest stars in the garage, Stewart has 48 career Cup wins in 542 starts but is winless this year and did not make the championship Chase field.

Sheriff Philip Povero spent weeks investigating, several times saying he did not have evidence to suggest Stewart meant to harm the other driver.

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

The sheriff asked in the days after Ward's death for spectators to turn over photos and videos of the crash as investigators worked to reconstruct the accident. Among the things being looked at were the dim lighting, how muddy it was and whether Ward's dark firesuit played a role in his death, given the conditions.

Tantillo also said two videos — one from a fan, the other from the tiny track in Canandaigua — had been examined and enhanced. The grand jurors "were not considering whether anybody else was at fault," Tantillo said.

"However, I am sure from their deliberations and discussions that the fact that Kevin Ward was observed running basically down two thirds of the track, into a hot track, into the middle of other cars that were racing, played a big, big factor in their decision," he said. "Realistically, I think judgment is probably the most important factor in this case."

Stewart vowed to cooperate in the investigation but he did not testify before the grand jury. He issued a brief statement expressing deep sadness and then dropped off the radar, missing races at Watkins Glen, Michigan and Bristol before coming back for the Aug. 31 race at Atlanta.

Stewart's peers were protective of him as questions emerged in the aftermath of the crash, and it pained them that Stewart was grieving in private and had cut off communication with so many of them. They welcomed him back in Atlanta, two CEO's from his top sponsors stood shoulder-to-shoulder with him before the race in a sign of support, and fans gave him a robust cheer, too.

NASCAR spokesman Brett Jewkes said there were "no winners" in the accident and expressed support for Ward's family and Stewart. Current Chase leader and 2012 NASCAR champion Brad Keselowski tweeted after the marijuana disclosure: "Can't believe what I'm reading about Tony Stewart's case. Why didn't they release this sooner?!?!"

After Ward's death, NASCAR announced a rule that prohibits drivers from climbing out of a crashed or disabled vehicle — unless it is on fire — until safety personnel arrive. The series also cleared the way for Stewart to make its Chase for the Sprint Cup championship with a win, despite missing the three races.

Stewart, who is from Columbus, Indiana, has long been one of the most proficient drivers in racing, winning in every kind of series, from sprint cars to the elite Sprint Cup Series. He has for years taken part in little races in nondescript towns because he loves the thrill of the high horsepower, lightweight cars skidding around the dirt.

He rarely made his schedule public, popping up when he pleased, and he was welcome at the clay track at Canandaigua Motorsports Park the night before the NASCAR race in nearby Watkins Glen.