LAS VEGAS — What police first described as the road rage-inspired killing of an innocent mother of four has morphed into a more complex scenario, prompting tough questions and a backlash against her family.

Tammy Meyers, 44, was shot in the head outside her home in a Las Vegas cul-de-sac shortly before midnight Thursday after confrontations that began when she was giving her 15-year-old daughter an after-hours driving lesson and the girl honked at a driver she felt was speeding, police said.

Those facts haven’t changed, police Lt. Ray Steiber said this week at a news conference, where he noted that the mother’s life-support was disconnected on Valentine’s Day, and insisted that she alone is “our victim.”

But the fatal shooting turned out to be a two-way shootout, provoked by an encounter with unidentified assailants, after Tammy Meyers had her daughter rouse her older son Brandon, who grabbed his gun and joined her in a hunt for the driver she had encountered earlier, Steiber said.

With questions lingering about the shooting and a murder suspect still at large, Las Vegas police held a news conference Wednesday at a busy intersection near headquarters in which they decried the dangers of road rage but did not discuss the investigation into Meyers’ killing.

The family spoke at a vigil Tuesday night next to the junior high school parking lot where Kristal Meyers got her driving lesson.

“She didn’t deserve this,” said Brandon Meyers, 22. “I did what I had to do to protect my family. Everyone can think what they have to think. I did it for a reason. And I’d do it for anyone I love.”

No one in the family called police until after the shooting, Steiber said, and initially, investigators had just the comments of the son and daughter to go on.

Meyers’ husband, Robert, who was in Southern California at the time, said Friday that his son Brandon told him he believed there were three people in the car, and that he had hit the car at least once with his 9mm handgun.