San Diego drivers who kill or injure someone with their car and just keep driving evade punishment almost nine out of 10 times.

And if they do happen to get convicted of their crime, it’s a coin flip whether they’ll serve more than two months in jail.

Those numbers come from a Voice of San Diego analysis of recent hit-and-run incidents and prosecutions. From 2009 through 2012, 4,100 drivers left victims dead or injured by the side of the road, according to information from the California Highway Patrol.

Over the same period, prosecutors convicted just 539 people of hit-and-run related crimes. That means 87 percent of drivers responsible for deaths and injuries were never punished.

The figures are a snapshot of a problem that’s becoming harder to ignore. By June of this year, more pedestrians had been killed by hit-and-run drivers than any time in the last five years.

Every few weeks since January, sometimes more often, police get a report of a body lying beside the road. Police chase leads, send word to media outlets and follow up on tips. But the police also say they’re virtually powerless to prevent hit-and-runs. As the data shows, they also rarely catch the people who are responsible for them. The District Attorney’s office only received a few dozen more cases from the cops than it successfully prosecuted.

In those instances, however, the punishments for hit-and-runs usually weren’t severe. In about half of convictions from 2009 through 2012, drivers were sentenced to less than two months in jail.

A Perverse Incentive

A moment of decision precedes all crimes. What sets hit-and-runs apart is that this decision comes after the damage is done.

For Nicoll Koval, her moment of decision came at 3 a.m. on Oct. 19, 2010.

Koval, then a 23-year-old nursing student, met a friend at a bar in Rancho Peñasquitos around midnight, according to a summary written by her attorneys in court documents. The friend introduced Koval to Albert Holman, who was celebrating his 34th birthday.

The three talked and drank beer, then Koval said goodbye and drove to another bar. There, she drank more and stayed until 2 a.m.  She grabbed a hot dog at a 7-11, and then drove toward home.

In a sordid twist, Holman, who’d been driving in the same direction, had gotten a pair of flat tires and was walking alongside the interstate.

She didn’t see him, her attorneys’ summary said: Her windshield wipers were at full speed. He was wearing dark clothing. And so on.

News accounts of the incident describe what happened next. Holman’s body shattered Koval’s windshield and crushed the hood of her car. She left the scene without stopping or calling 911. After she got home, a neighbor heard Koval crying in her driveway, telling her father over the phone that it wasn’t her fault.

After contacting an attorney, Koval turned herself in to police the following afternoon and allowed them to impound the vehicle. That’s when police found an empty can of malt liquor in her car and one of Holman’s shoes still hooked to the car’s undercarriage.

In court, Koval’s defense was typical of those charged with hit-and-runs: She didn’t know she’d hit or killed anybody. She ended up pleading guilty to felony hit-and-run causing death and was sentenced to a year in jail and three years of probation.

This situation could reveal a perverse incentive within hit-and-run laws – beyond the fact most of the time if you leave the scene you’re not going to get caught. Legally speaking, it might have actually been in Koval’s best interest to flee. Prosecutors might have believed she’d been drinking when she hit Holman, but couldn’t prove she’d been intoxicated.

Had she stayed at the scene and police found that her blood alcohol content was above the legal limit, she might have been charged with gross vehicular homicide and faced 10 years in prison. Instead, her felony hit-and-run charge carried a four-year maximum sentence.

Dave Greenberg, a chief deputy in the District Attorney’s office, said the state has tried to develop certain stiffer punishments for drivers who flee the scene of accidents to deal with this issue. For example, if drivers are guilty of gross vehicular manslaughter, they could serve 10 years in prison. If they leave the scene, they’d face a 15 year maximum sentence.

Regardless, hit-and-runs have rarely resulted in substantial sentences here. Koval’s one-year jail term far surpassed the two-month or less sentence that the majority of offenders received between 2009 and 2012.

‘I Don’t Know The Answer’

Greenberg said prosecutors need to hold offenders accountable for the crime, but must consider the individual circumstances of each case.

For this reason, sentences frequently include probation or alternative kinds of incarceration – like work furlough programs which allow offenders to work during the day but return to a facility at night or and on the weekends.

“Let’s say a driver hits someone with his car, and breaks the victim’s arm,” Greenberg said. “The driver panics, and drives away. Now, I don’t condone that. I think it’s terrible. But do we want that driver to go to jail and lose his job – or do we want the person to keep working and making money in order to pay the victim restitution for his hospital bills?”

In terms of whether stiffer punishments could prevent more hit-and-runs from happening, Greenberg had mixed thoughts.

There’s reason to believe increased legal sanctions for drunk driving, coupled with increased education, helped decrease DUIs since the 1980s, he said.

“But there’s a different dynamic with hit-and-runs,” he said. It’s difficult to know whether drivers would consciously weigh the pros and cons of running after they hit someone with their car.

This fits with research from experts at UC Berkeley’s Safe Transportation Research and Education Center.

Research director Offer Grembek said the idea that crime will be deterred by fear of punishment hinges on the belief that a crime will be met with certain, severe and swift consequences.

One of the most successful pieces to crime deterrence, Grembek said, is a robust public information campaign that educates the public about the damage of hit-and-runs – in the same way drunken driving messages are effective.

But with few punishments after hit-and-run incidents, this piece becomes more difficult.

“I wish I could tell you the best way to stop these from happening,” Greenberg said. “But I don’t know the answer.”

Gonzalo Urrutia, Hila Hashemi, Kenny Law, Kevin Hung and Rajat Shah of the San Diego Regional Data Library contributed to this project.