By Tiffany Walden, Orlando Sentinel (TNS)

ORLANDO, Fla. — When traffic investigators arrive at the scene of a fatal hit-and-run — a crime on the rise in Florida — the only clues might be some skid marks, or a few fragments from the car that fled.

What may seem like debris strewn across the highway, however, is investigative gold to traffic-homicide detectives trying to find the car and its driver.

Detectives hit the jackpot in September 2010 while sorting through the pieces of a broken chrome car grille after a driver killed a pedestrian on Landstar Boulevard near State Road 417 in Orange County and kept going.

One of the pieces was imprinted with a part number.

“That grille made for that car was one year only,” said Cpl. Brian Gensler of the Florida Highway Patrol’s Central Florida troop. “Every year, they change the dynamics of cars, so that (grille) was changed on that car.”

The part number led investigators to a black 2004 Cadillac Escalade with a Georgia license plate registered to Edgardo Martinez-Rivera, according to Gensler.

After investigators issued a “be on the lookout” to Florida law enforcement agencies, an Orange County deputy spotted the abandoned car Oct. 11, 2010, while on patrol near the Citrus Bowl — about 20 miles from the crash site.

The paint from the Escalade’s hood matched paint fragments left on the victim’s shirt from the impact of the crash. And a cigarette butt found on the driver’s side of the vehicle provided a DNA sample, court records show.

Martinez-Rivera served 218 days in jail for leaving the scene of a fatal crash. He is on probation until 2022.

“If we don’t have the (hit-and-run) car or the person, we’re looking for debris,” Gensler said. “From there, you’re looking for a serial number or type number from the car. That’s the biggest key if you don’t have the car or the person.

“Soon as (the crash) occurs, the clock is ticking,” Gensler said. “Usually the first 48 hours are critical, collecting and notating all the evidence.”

Such CSI-like techniques are increasingly important as the state contends with an increasing number of fatal and nonfatal hit-and-runs. In 2014, the FHP reported more than 80,000 hit-and-runs in Florida — up 7 percent from 2013.

Bill Barge, a retired 32-year FHP veteran, spends his retirement mentoring and training future traffic-homicide investigators on the science behind solving a hit-and-run.

He said DNA is the most important piece of the puzzle because the biological material — such as fingerprints and blood — can tell investigators exactly who was driving the hit-and-run car at the time of the crash.

“No matter what we do, we have to put (the driver) behind the wheel,” said Barge, 69.

Many times investigators have neither the car nor the driver at the scene. Other times the person responsible for the accident will leave the car behind and flee on foot.

Police say that’s what happened in a recent fatal rollover crash on U.S. Highway 441 in Apopka.

The driver jumped from the car and left his passenger dead inside.

“When we got there, we had a shoe right outside the driver’s door,” Apopka police Officer Ashley Eller said.

Officers eventually found the driver — with the other shoe still on — hiding near a retention pond not far from the scene.

The investigation doesn’t stop there. Detectives still have to find evidence placing the driver behind the wheel in order to have successful prosecution in court.

Eller couldn’t speak about the specifics because of the ongoing investigation.

But Sgt. Steve Gaskins, of FHP’s Tampa region, pointed out the importance of an air bag in a situation like that.

“The air bags are going to have the DNA of the person it struck,” Gaskins said. “All I need to know is who the driver’s air bag hit. That’s the crucial part.”

Barge added that the Florida Department of Law Enforcement, which processes DNA and other evidence in criminal cases, will use laser technology to pull a shoe print off the accelerator or brake.

Then detectives can match the shoe print to those on the bottom of the suspect’s shoes.

“No evidence is too small,” said Brian Rodriguez, a 16-year officer with the Altamonte Springs Police Department. “If you don’t gather your evidence the proper way, you can lose a case. So everything you do from start to finish is very important.”

Photo: Officer Ashley Eller of Orlando Police Department’s traffic homicide division gestures towards a wrecked vehicle on August 4, 2015. (Tiffany Walden/Orlando Sentinel/TNS)