A Marine Corps veteran’s cross-country “thank the police tour" stopped in Dallas Thursday morning.

Billy Richards, now a trainer and athlete who lives in New York, started the tour last Friday. Dallas was his 22nd stop on the journey, which he said was inspired by negative publicity for the nation's police force.

“It’s just [to] raise awareness and bring a positive side to the police departments,” he said. “There’s a human side to everything”

Richards bought 30 American flags before departing on the "thank the police tour." Once he arrives at each police station, he runs three to five miles with an American flag. Some of those trips -- like Thursday’s in Dallas and one days before in Baton Rouge -- take him to the site of a tragedy, where he raises a flag and observes a moment of silence for the victims.

On Thursday, his trek took him to El Centro College, in the same street blocks where five officers were gunned down in an ambush-style attack on July 7.

“It’s always kind of mind-blowing to be at the site where things have actually happened,” he told News 8. “It’s kind of like a dark cloud effect that comes over you and it really hits home.”

After stopping to honor the victims, Richards returns to the police department. He gives them the American flag, along with a handwritten “thank you” note.

In each note, he writes a list of everyone who helped make his trip a reality -- so far 90 people have assisted, he said.

Richards, who spent four years in the Marine Corps and three in the U.S. Army, said he can relate to members of law enforcement.

“As far as I’m concerned, law enforcement [officers are] kind of like brothers,” Richards said. “We [in the military] defend the country overseas, and they defend the country on the homefront.”

He began his tour by stopping at each precinct in his homeotwn of Long Island. He visited police departments in Philadelphia and Baltimore before traveling down the east coast, stopping in several cities including Orlando and Baton Rouge.

His 21st stop was in Beaumont on Wednesday.

Up next for Richards? A 13-hour drive to Arizona, before stops in California, Denver, Chicago, Cleveland and back home, he said.

Billy talked about his mission in a live stream on Facebook Thursday. You can help him by donating to his GoFundMe campaign here.