LAKE WALES, Fla.— The reward is now up to $10,000 for information leading to an arrest in the case of a deadly hit-and-run that left one woman dead and a Polk County Deputy severely injured.

A deadly crash… Few clues… One witness killed, the other severely injured.

So how likely will it be that investigators track down the driver responsible?

“The first thing they need to figure out is what happened here,” said crash investigator Kirby Lavallee, who previously served on the Hillsborough County Sherriff’s Office DUI squad and now runs his own private investigation firm, Sharpline Investigations.

He says many hit-and-runs involve driver impairment.

“They’re all over the road. They don’t know what they’re doing. Their perception of distance and time is off. By the time they even realize they hit something they could be several hundred yards down the road,” said Lavallee.

“Then they go into panic mode, saying ‘Wow, if I get caught and I’m impaired, what’s going to happen to me?’ They just flee the area and they go home. They ditch their car and they run.”

Hit-and-runs often go unreported for hours or even days, putting detectives at a disadvantage.

“Obviously the first thing we start doing is canvassing the area,” said Lavallee. “Broken lens covers, maybe a piece of your bumper and a lot of these cases have major impacts where they leave the whole bumper.”

But finding the vehicle is only part of the puzzle. Proving who was behind the wheel can be an even bigger challenge, and that’s where cameras come in.

This week, a driver in Pinellas County was caught on camera at a nearby business after investigators say he caused a four-car crash, then took off on foot.

“Maybe this area over here doesn’t have any cameras… we would look even back further,” said Lavallee, pointing to camera at a nearby store. “Or maybe the traffic light they passed through has a camera.”

The big break can even come days or weeks later.

“Typically with any type of crash people want to get their car fixed, so typically this car is going to go to some type of body shop or some insurance company is going to be notified of it,” said Lavallee. “Especially in the case where a vehicle hits a person: that’s a distinct kind of damage.”

Leaving the scene is often bad news for everyone.

“It’s not going to be any better for you if you wait to turn yourself in,” said Lavallee. "But it could be worse if you leave, because you’re not only going to be facing the charges that you had, but you’re going to be facing additional charges if you leave.”