Kristal Meyers says she still replays the night her mother Tammy Meyers was shot and killed in their driveway nearly a year ago.
"I just think about looking out the window mostly and seeing her fall," Kristal Meyers, 16, told ABC News' "20/20" in an exclusive interview. "I just wonder, like, why it all happened. Just why would somebody would want to kill somebody?"
Tammy Meyers, 44, died on Valentine's Day, Feb. 14, 2015, two days after she was shot in front of her Las Vegas home after taking Kristal, then 15, for her first driving lesson.
Erich Nowsch Jr., 19, who lived a block away from the Meyers family, was charged with conspiracy to commit murder, murder with use of a deadly weapon, attempted murder with a deadly weapon and discharge of a firearm from or within a structure or vehicle, in the death of Tammy Meyers. A second suspect, Derrick Andrews, 26, who prosecutors allege drove Nowsch to the cul-de-sac where Tammy Meyers lived, also faces the same charges.
Kristal Meyers said she and her mother went out for a driving lesson at night on Feb. 12, 2015, because she thought there would be fewer people on the road. "I wanted to go at night because there's no one around that you could possibly hit," Kristal Meyers said.
The lesson ended around 10:50 p.m. local time, according to police, and Tammy Meyers got behind the wheel to drive them home. On the way, Kristal Meyers said they were confronted by a driver in a silver car.
"I just noticed that he was like riding our bumper. He swerves around us, and I honk the horn," said Kristal Meyers. She now wonders what if she never reached over and honked the horn on her mother's 1993 Buick.
Later on, Kristal Meyers said the silver car suddenly side-swiped their car, and then the driver got out of the car and started yelling at them and threatening them.
"And he says, 'I'm going to kill you and your daughter,' and he's cussing and he's raving," Kristal Meyers said. "I just remember that he had light brown hair. He had no tattoos or piercings, and he was just yelling and screaming."
Tammy Meyers then pulled into their driveway, and Kristal got out of the car. Tammy asked Kristal's brother Brandon Meyers, then 22, to come with her to search for the silver car. Brandon Meyers told "20/20" he took his gun, a registered Beretta 9-millimeter pistol, to protect his mother and left with her in the car.
While his mother was driving, Brandon Meyers said he asked her what happened. He says he hid his gun in between his legs and never waved it or threatened anyone. When they arrived at the scene where Tammy Meyers said she and her daughter were allegedly side-swiped, Brandon Meyers said they didn't see any cars and agreed to go home.
"I'm still on edge, you know," Brandon Meyers, 23, told "20/20." "No one's near us, completely. It's a ghost town."
But on their way home, Brandon Meyers said his mother suddenly said that she saw the silver sedan she believed hit her earlier sitting right in front of them.
"Basically, when she sees the car, [she said], 'Brandon, that's them. Those are the ones that threatened to kill me and your sister,'" Brandon Meyers said.
Brandon claims that car took off, and he and his mother pursued them. But suddenly the car stopped, and a person in the car, who police believe was Erich Nowsch, then began shooting at them, Brandon Meyers said.
"She goes, 'Brandon, what was that?' And I said, 'Mom, we're getting shot at.' So, at that point she's shaking," said Brandon Meyers.
Brandon said they sped away trying to get out of the line of fire and into their home. The car, which police said was driven by Derrick Andrews, minutes later, returned and followed them into the cul-de-sac where they lived.
"[I didn't think there was going to be a shootout] until they started shooting. And then it was just -- I blacked out. Like, at that point when I saw them coming down, like, my heart just stopped. All this adrenaline built up, and that's where it all went down," Brandon Meyers said.
Police said Nowsch then opened fire on Brandon and Tammy Meyers. "There's no evidence to suggest that Brandon Meyers showed anything that would be enough of a threat to justify Mr. Nowsch's actions," Clark County District Attorney Steve Wolfson told "20/20."
When the shooting ended and the silver car drove away, Brandon Meyers saw his mother on the ground. She was struck by a bullet in her left temple. Inside the family home, Kristal Meyers said she heard the gunshots -- 22 rounds police say came from Nowsch's .45 caliber Ruger.
Kristal watched her mother fall from a window.
"I was checking her body to see where I could find the wound, and then, like right there, I saw the hole," Brandon Meyers said. "And I hate looking at this. Every day before I go to work, I just stare at the ground right there. And I know that she was right there."
Police arrested Nowsch on Feb. 19, 2015, during a two-hour standoff at his home -- just a block away from where the Meyers family lived. The alleged driver, Derek Andrews, was arrested a month later on March 20, 2015. Andrew's attorneys claim there is no evidence that placed him at the scene the night Tammy Meyers was killed.
Both Nowsch and Andrews are in custody and awaiting trial. Trial is scheduled to begin next month.
But defense attorney Conrad Claus said he believes this is a case of double mistaken identity. He said Nowsch -- not Tammy Meyers -- may have been the target the night that she and her daughter were allegedly threatened and that an unknown shooter thought she was Nowsch, and Nowsch confused Meyers with the unknown shooter and tried to defend himself.
"The facts seem to point to self-defense in this situation," Claus told ABC News in an exclusive interview. "It seems to explain the facts we have in front of us more sensibly than any other explanation."
"The evidence will show Mr. Nowsch, in an unprovoked way, for stupid reasons, chose to drive down in a neighborhood that he was familiar with, and he saw two people and opened fire," Wolfson told "20/20."
This week Tammy Meyers' husband Bob Meyers and their four children moved out of the neighborhood because it is a constant reminder of what happened to her, the family said.
"I catch myself all the time calling her. I'll sit in my chair out in the living room, and I'll go, 'Hey, baby.' Nothing comes back no more," Bob Meyers told "20/20."
Bob Meyers said he is waiting to lay his wife's ashes to rest until after Nowsch's trial starts next month.
"Because everything that was said about my wife, when I put my wife in the ground, I want all the truth out. And I think the only way we're going to get that out is from a trial, 'cause I know there's a whole bunch more evidence about that night," said Bob Meyers.
Brandon Meyers said he gave away the gun he took with him that fateful night.
"The cops have it," Brandon Meyers said. "I told them I don't want it back. They can keep it."
Kristal Meyers, who is the youngest Meyers child, started home schooling after she said bullying took a toll on her and she is still dealing with feelings of guilt.
"I ask myself, 'What if we didn't go?' or 'What if I didn't want to go?' or 'What if I never honked horn?'" Kristal Meyers said. "It probably would have been different."