Among the people to participate in Saturday's March for Our Lives was Paul McCartney.

The musician said this particular issue hits especially close to home.

"You know, I'm like everyone. I don't know. But this is what we can do, so I'm here to do it," McCartney said. "One of my best friends was killed in gun violence right around here, so it's important to me."

McCartney's Beatles bandmate John Lennon was shot and killed on the Upper West Side in 1980.