(CNN) -- The Facebook photo, grainy and blurred, shows a boy in his Cub Scout uniform standing in the sun on the side of the road, his right arm in a stiff salute as cars pass by in Woodlawn, Virginia.
The caption tells the rest of the story. Nine-year-old Lane Snow salutes the two-mile funeral procession Thursday for Virginia State Police Trooper Andrew Fox. The trooper, a graduate of Virginia Tech, was run over and killed while directing traffic at the state fair earlier this month.
When the photo landed in Virginia Tech police Lt. George Jackson's inbox, he knew it would be a hit. Jackson manages the social media accounts for the college police department and posted the photo Friday in two places on the department's Facebook page. He asked fans to share the photo "and see how many likes we can get for this young Boy Scout and his tribute to Trooper Fox!"
The first day, the image of Lane Snow's salute received 15,000 shares. The next day it had 45,000. By Tuesday it had been shared more than 68,000 times and growing, reaching an estimated 4 million people, according to Facebook's own analytics, Jackson told CNN. He had no explanation for the numbers of shares except to say the comments reveal a community who supported Snow's character.
Lane Snow didn't know trooper Fox, but he told local station WDBJ7 he did it because "I was sorry that Andrew Fox died." Snow's parents told the station he came up with the idea to dress in uniform and salute the procession on his own.
Everyone who saw it was touched, including Fox's widow, who saw Snow saluting as her car passed, WDBJ reported.
It was a pure and touching gesture, Jackson said.
In an interview with CNN, Jackson said he wanted to bring awareness and attention to the state police and Fox's family as a measure of support.
"I just remembered how it felt to have lost an officer. The community rallied around us," Jackson said.
At Snow's Cub Scout meeting Monday night, 10 officers from various agencies -- some of whom knew Fox personally -- showed up to thank Snow in person, said Cub Master Darrell Lineberry.
Lane Snow told the local station that he wants to be a policeman when he grows up, "just like Andrew Fox."