They risk their lives... and yours.
Serious crashes caused by gangs of motorcycle stunt riders are on the rise. In July, they caused a wreck on Interstate 45 that killed two innocent motorists.
Law enforcement officials say they're virtually powerless to stop the problem.
But News 8 has discovered that some authorities may not be investigating the basic clues that could bring justice to victims.
Generally, police do not chase sport bikers. A high-speed pursuit just puts the public in additional jeopardy.
But Many North Texas drivers know the fear of a gang of sport bikers blazing past you; or standing by helpless as hundreds of riders shut down an entire Dallas freeway, as they did last Memorial Day.
"It makes you think you're either a split-second away from killing somebody or being killed," said motorist Brenda Kozakis.
That's what happened to Preston Cass in September. He was on the Dallas North Tollway, riding too fast in a group of ten speeding bikers.
The lead bike was doing wheelies, riding only on its back tire. Cass rammed into the back of a pickup truck, crashed into a wall, and died at the scene.
The other riders fled, failing to render aid.
Cass lived with his grandfather, Bill Blythe. "I just wish those kids would slow down, because it's going to happen again," he said.
The Cass family says it has a good idea who Preston was riding with that night. But it's been almost two months since the crash, and the family says no officer or detective has ever called or stopped by to ask about the incident.
The Texas Department of Public Safety is handling the investigation.
"It's public safety," said DPS spokesman Trooper Lonnie Haschel. "In this case, the case is still open. So, I don't have any information if they found that or not."
But it wasn't hard for News 8 to find hours of video of law-breaking stunts posted online by a club called the Dallas Stunt Riderz. Sources say one of the featured riders is 24-year-old Thomas Warren Cowley.
Cowley is a convicted felon serving five years probation for evading arrest on his sport bike in 2009.
Cowley denied he was at the scene of Preston Cass' fatal crash. Police have not named him — or anyone else — as a suspect.
"How serious are you about stopping this if you don't run all the traps?" News 8 asked Trooper Haschel.
"Again, public safety is first and foremost. Department of Public Safety. It's what we're all about," he replied.
Bikers aren't just killing themselves. They are also responsible for the death of Voncilla Franklin's brother, 36-year-old Jonathan Franklin.
"They need to be stopped, because people are losing their lives behind that," Franklin said.
In July, Jonathan Franklin was driving in a car on I-45. A pack of about 14 sport bike riders — traveling in the wrong direction — caused a wreck that killed Franklin and his friend, Derrick Finch.
"There were a lot of motorcycles passing by really fast," said Noemi Marquez, who was involved in the crash.
The Dallas County Sheriff's Department, which is investigating, said the wrong-way bikers had circled back on the freeway to check on Brandon Hollis, one of their own riders who had fallen.
While talking to Hollis could be an important part of an investigation into a wreck that killed two people, Hollis told News 8 that no one from the Sheriff's office has interviewed him about who he had been riding with that day.
It's an important question when innocent people are dying.
"Now the people that lost their family have to deal with this," said Voncilla Franklin. "We have to deal with this."
And families are suffering.
Bill Blythe is trying to follow his pastor's advice. "You'll never get over it, but you'll get through it," he said. "I hope he's right."
Law enforcement says addressing this threat to public safety is a challenge that will require agencies across North Texas to work together.
That's means both patrols and investigations.
Without that effort, bikers will continue to openly break the law, killing themselves and innocent victims.