WSMV-TV NASHVILLE

A $10,000 reward is now being offered for information leading to an arrest and conviction of whoever murdered Saint Thomas West nurse Caitlyn Kaufman.

Police said a local man posted the reward and wants to stay anonymous.

Kaufman was shot and killed on Interstate 440 Thursday evening when she was on her way to work.

Ascension Saint Thomas released a statement about Kaufman’s death on Tuesday.

“Those who knew Caitlyn Kaufman witnessed the overwhelming compassion and kindness she showed for each person she cared for and worked alongside during her two years in Ascension Saint Thomas Hospital West’s ICU. Every life she touched was warmed by her smile and gracious spirit. Caitlyn loved her patients and was so proud to serve alongside the other selfless caregivers in her unit,” the hospital said in a statement.

Police said they are certain the murder happened between 6:05 and 6:10 on Thursday night.

When asked why, they couldn’t elaborate, but said science.

Experts News4 spoke with said a lot can be learned from a single picture.

Kaufman was on I-440 when six bullets were shot into her car.

Shane Kerwin, a retired Special Forces sergeant who specialized in sniper shooting and medical response, said based on the picture of Kaufman’s car, he thinks the shooter came up from behind. He also believes there was more than one person in the car, someone to drive and someone to shoot.

“If you think about how the lanes are set up on 440, that would be mere feet from that window to the window and the door of the vehicle they were shooting into,” said Kerwin, now a training manager at Royal Range in Bellevue.

Kerwin said using a handgun, firing six shots into a car while traveling 55 miles per hour is easier than one might think.

“Now if they were driving and they had a rifle, it would be a completely different scenario. It would be a lot more difficult,” said Kerwin.

As for what witnesses would have seen and heard?

“If somebody was close in another car on the side of the road, they might have been able to hear the gun shots if they were able to understand what it actually was,” said Kerwin. “They would definitely see a flash because the lighting was low.”

Police said Kaufman died within 15 seconds of being shot. Kerwin said that’s because of where she was shot – her left shoulder.

“We have lungs, big vessels, heart, another lung,” said Kerwin. “If we hit multiple things and there’s multiple-system trauma, that time could be expedited quite a bit.”

Kaufman’s car is currently in a police bay being analyzed. If investigators recovered bullets, they will be able to determine exactly what kind of gun was used.

If they can find the gun, they will be able to link it to the crime.

Even though TDOT Smartway cameras pointed right at the crime scene, police do not have video of the murder because those cameras do not record.

Here are some crucial details police are working with.

Kaufman was shot between 6:05 and 6:10 Thursday night on I-440 West. They said she died in seconds after the bullet went through her left shoulder. She had no time to call 911.

The nurse wasn’t found until more than 2-1/2 hours later.

If you were on I-440 anywhere between the West End and Hillsboro Pike exits Thursday night between 6:05 and 6:10, police want to hear from you.