For three years, Sgt. Tracy McDonald witnessed the worst valley roads offered.
He was head of the Metropolitan Police Department's fatal detail. He investigated traffic deaths.
The veteran cop saw it all; more than 420 bodies.
There were the innocent victims. And the guilty ones.
The reasons were many. Death came at the hands of drunken or drugged drivers. Speeding. Impatience. Drowsiness. Distractions. Motorists that ran red lights and stop signs. Drivers who didn't wear seat belts and some who did.
There was the investigation into a Nevada Highway Patrol trooper who crashed into a Cadillac at more than 100 mph, killing four. The trooper would go to jail. There was no reason for him to have been driving that fast.
There was Veronica Schmidt, who drove an SUV into a bus stop, killing four. She was on prescription drugs.
It was three years of mangled metal, broken glass and blood-soaked asphalt.
McDonald was called at all hours, day or night.
No more. He retired in December.
"I didn't mind," he said of the late night calls. "It was a job that needed to be done."
In some respects, McDonald put his life on hold for three years to serve the valley.
Such a detective gets called out a lot in Las Vegas. Because he was a supervisor, McDonald responded to almost all of the fatal accidents under his watch.
There were tough stretches. Like the one in March 2005 when 14 people died on valley roads in three days.
But he felt it was a noble burden. McDonald and his team spoke for those who couldn't.
"Our goal was making sure we did everything we could to prosecute those responsible to the fullest extent of the law," he said.
And it was intriguing. There's a lot of science to crash investigations. There's physics and geometry. Each detective has more than 500 hours of training, he said.
McDonald hails from Rochester, N.Y. He was studying to be a cop at a community college when his older brother called from Las Vegas. "He told me the Police Department was growing and was offering a lot of opportunities like K-9 and SWAT that you couldn't get locally."
In June 1980, McDonald packed a van and headed west.
McDonald worked in the traffic bureau for most of his career. He investigated wrecks. He supervised training. He rode a motorcycle beat.
He learned quite a bit in more than 27 years on the job.
Surviving the streets of Las Vegas comes down to driving 101, McDonald teaches.
"It's just so simple. Follow the rules of road. Slow down. Use defensive driving skills. Cut down on the many distractions in our vehicles, whether it's text messaging and cell phones" or DVD players, he said.
There's some luck involved, too. Luck can go both ways, so McDonald encouraged people to buy well-manufactured vehicles.
In case you were wondering, McDonald drives a GMC Yukon.
"I never took a dead body out of a Yukon," he said.
McDonald added that he's trying to do his part for the environment, too, by purchasing a Yukon with a flex-cylinder system. His Yukon switches from an eight-cylinder to a four-cylinder on it's own to reduce the amount of gasoline it uses.
McDonald still scratches his head about the state Legislature's inability to make failing to wear a seat belt a primary offense. It is a secondary offense, so police cannot pull someone over for not wearing one.
"It's very frustrating. It's the No. 1 safety factor that drivers can take advantage of," McDonald said. A little bit of enforcement would go a long way in saving lives, he said.
When McDonald retired he headed back east to New York. His mother had been suffering from Parkinson's disease, among other ailments. He went home to help his father care for her.
Within three days of his arrival, his mother took a turn for the worse. She passed away about two weeks later.
"She was proud of me. It was touching hearing that from her. Being by her side. ... I'll take that with me for the rest of my life," he said.