A truck veers off a parkway in Nashville slamming into trees. The driver inside -- dead.

But as officers respond to the scene they soon realize this isn't a tragic accident.

A truck loses control on an empty stretch of highway, crashing into the woods near Nashville, Tennessee on Sept. 28.

The driver, Ryan Trent, who was about get married, was pronounced dead at the scene.

Ryan Trent was a loveable guy. A free spirit who was happiest riding his motorcycle, Ryan had recently turned his life around, proudly conquering the demons of drug addiction.

"I was so proud of him. That's all I wanted for many years to see the old Ryan back," said Ryan's brother Brandon Trent. "Just to see him doing so well, I was very proud of him," said Brandon.

And Ryan was about to get married to the love of his life, Brittany Robinson. His fiancée says without Ryan she doesn't know where she would be.

"He was just a kind soul. He showed me that there was just a better way to live. He cared and loved me for who I was," Brittany tells Crime Watch Daily.

Ryan's family is devastated by the deadly crash. At first, it appears he had fallen asleep at the wheel driving home at 2 a.m. from his late shift as a supervisor at a parking garage.

"We didn't find out until later that night that he had been shot," said Ryan's mother Sharon Trent.

"The medical examiner found a bullet inside Ryan Trent's skull," said Metro Nashville Police Detective Adam Weeks.

And the news from the medical examiner comes hours after what cops thought was an accident.

"It went from a fatal traffic crash to a homicide," said Det. Weeks.

But who would want to kill Ryan Trent? According to investigators, that fateful night Ryan and fiancée Britney exchanged a frenzy of 86 texts during Ryan's seven-hour shift. Homicide detective Adam Weeks hoped those text messages might contain a clue.

"There's no mention of anything going awry. She said that he would have mentioned if he had any problem with anybody," said Weeks.

But an hour after his last text, Ryan was dead. And the mangled pickup truck's navigation system didn't give cops much to go on either.

"It determined that he was driving at about 55 to 60 miles an hour and during that 12 seconds did not accelerate. The vehicle comes to a rapid stop when it hit the tree," said Weeks.

Did Ryan get into a beef with someone at work? Could it be a random shooter? Or did he tick off another driver in a road rage fight?

"Ryan Trent's vehicle's driver's window was rolled down, there could have been something yelled out of a window. Unfortunately it just takes something as simple as that," said Weeks. "Where most people would honk a horn or raise a finger or yell a swear word, other people will fire a shot or two at the vehicle."

They post signs offering a reward for his killer. The family is up in arms. They don't believe what cops say went down. A single shot fired in a road rage incident. They go back to the scene of the crime to search for clues themselves.

"We went down there, we had metal detectors looking for evidence," said Glenn Trent.

And there they find something that stops them in their tracks.

"They said one shot killed him but it looked to me like there was more than one shot," said Glenn. "We found some evidence we felt pretty highly of."

Spent cartridges in the same area where cops had searched before. But there's more. Cops reveal there's been a rash of highway shootings: four road rage incidents in the span of a week.

"Two of them, including Ryan Trent, resulted in homicide," said Det. Weeks.

Now Ryan's family wonders: Could there be a homicidal maniac on the loose, turning a stretch of Ellington Parkway northeast of Nashville into their personal killing field?

"I hope they have nightmares every time they shut their eyes," said Sharon Trent.

But Det. Weeks thinks the shootings on the highway are not connected.

"The evidence tells me that it's more likely a stranger-on-stranger crime than it is a targeted crime," said Weeks. "I don't believe that anyone had anything against Ryan Trent until a few seconds before they shot Ryan Trent."

Now Ryan's family is asking for your help to catch his killer, wondering if anyone else was on that stretch of Ellington Parkway early that terrible morning when the fatal shot was fired.

"I just feel like there's somebody out there that knows something, and I just beg them to come forward with what information you have," said Sharon.

Ryan Trent's family gathers around the dining room table. The good times they shared with Ryan are framed in the pages of photo albums. But his family cannot rest until they find the person who took Ryan away.

"Even to this day, I may look the same on the outside but I never will be again on the inside," said Sharon Trent.

If you saw Ryan Trent's truck the night of the murder or know anything about the crime, contact Nashville Crime Stoppers at (615) 742-7463, or submit a tip to Crime Watch Daily. You can remain anonymous.