When asked by the reporter why he was there, McCartney simply took a step back to show off his "We Can End Gun Violence" t-shirt.
While the March for Our Lives rally in D.C. was the biggest, it was by no means the only rally in the country on Saturday.
"I'm like everyone", McCartney told CNN.More news: Why Mohamed Salah can't be compared to Lionel Messi: Watford boss explains
Lennon was murdered by Mark David Chapman on December 8, 1980 outside his NY apartment. "I invite you to give us your brain power".
Marjory Stoneman Douglas High School students Emma Gonzalez, Alex Wind, David Hogg, Jaclyn Corin, and Cameron Kasky planned the March for Our Lives in Washington D.C. days after the February 14 mass shooting at the Parkland, Florida. Common, Ariana Grande, and Miley Cyrus were scheduled to perform at the Washington, DC rally, which reportedly brought around half a million people to the nation's capitol.
McCartney, 75, was joined by his wife Nancy Shevell on Saturday during the March for Our Lives on Manhattan's Upper West Side when spoke off-camera to CNN's Jason Caroll.
There were more than 800 marches across the USA and the world.