The two Triton High School teens were air lifted from the crash scene to WakeMed, but Moore didn't make it.
Tart says he is heartbroken and haunted by a tragedy, he says, he doesn't remember.
"Sometimes I do wish I could remember what happened, other times I don't want to remember at all," he said.
The high school student was behind the wheel of his SUV on June 4 when it roared through the Wal-Mart parking lot, hit two vehicles, flipped and then slammed into the store's fire exit doors and a portion of a brick wall.
Tart's 16-year-old girlfriend was in the passenger seat when the crash happened.
"The last thing I remember is waking up at WakeMed in Raleigh," he said.
Tart says he did not know what had happened until his parents told him.
"(I was) shocked, very shocked," he said. "I don't remember nothing at all."
Eyewitnesses reported that the couple argued in the parking lot of a gas station near the Wal-Mart store before the SUV sped off.
"I know it was a tragic accident," Tart's mother Patricia Jackson said. "I know in my heart he would never hurt her."
Jackson says talk and rumors of a sinister or intentional motive behind the accident are simply untrue. But many in the Town of Dunn say, at this point, they don't know what to believe.
"Dillon had his first seizure back in 2007," she said.
Jackson says she has medical documentation that Tart suffers from infrequent seizures, and she believes that's what happened the day of the crash.
"When Dillon has had a seizure he stretches his arms, he starts shaking and his legs are like in a stretching position," she said. "And a lot of people … are saying 'why didn't his mother have him on medicine?' Well I got documents from Chapel Hill doctors; they told me he don't need medicine if he gets sleep."
Tart and Moore were high school sweethearts and had dated for over two years and Tart says he would never do anything to hurt the love of his life.
"I just want everyone to know I did not intentionally hurt her, I didn't mean for any of this to happen," Tart said.
An 11 page police report doesn't say what or who caused the accident. Currently, there have not been any charges filed against Tart.
At this point, the Harnett County district attorney will only say that she will review the investigation police are wrapping up on Thursday and will present it to the Harnett County grand jury on Monday.
Testimony from a couple of eyewitnesses and video taken by cameras on the front of the Wal-Mart will also be presented to the grand jury.