Darnella Frazier, whose viral video of George Floyd's murder by Minneapolis police shook the nation's conscience about policing and racism, shared a public reflection Sunday.

In an Instagram post, she called that day five years ago "a traumatic experience in my life" that she tries to forget but cannot.

Frazier was a 17-year-old heading to a corner market on May 25, 2020, when she came upon the scene of Floyd dying under the knee of a Minneapolis police officer.

She recorded the killing on her cellphone and shared it with the world, an act that was key in four officers being convicted and imprisoned.

Five years to the day since Floyd's murder at 38th Street and Chicago Avenue, Frazier directed her thoughts to him and wrote, "I sometimes catch myself feeling guilty for trying to forget and block it all out, because it's such a traumatic experience in my life. But truthfully, I could never forget about you. Your name still echoes, and I'll never be silent."

On Sunday, crowds trekked to 38th and Chicago — what's come to be known as George Floyd Square — to celebrate his life and legacy. A steady stream of people paid their respects at a memorial in front of Unity Foods, formerly known as Cup Foods, where he was killed.

Across the street, activists set up a feeding area at a former gas station that has often served as a staging area since Floyd's death. In the middle of the street, a fake pig's head was mounted on a stick. The head wore a police cap.

In Houston, where Floyd grew up and is buried, the Rev. Al Sharpton said at a graveside service that Floyd, 46, represented all of those "who are defenseless against people who thought they could put their knee on our neck."

Frazier is now 22 years old. She has lived her life out of the spotlight and is careful to protect her privacy since Floyd's murder.

The world got glimpses of her when she testified in the livestreamed trial of Derek Chauvin, the officer whose knee took Floyd's life.

"When I look at George Floyd, I look at my dad, I look at my brothers, I look at my cousins, my uncles, because they are all Black," Frazier said in court, her voice faltering as she testified against the white defendant.

In December 2020, Frazier received the prestigious Benenson Courage Award from PEN America from Oscar-winning director Spike Lee in a virtual ceremony that included recognition by other notables.

In June 2021, the Pulitzer Prize Board started its annual announcements for outstanding journalism by issuing a special citation to Frazier.

On Sunday, in one of her rare public postings about that day, the 22-year-old Frazier wrote on Instagram, "I sometimes forget how supported I am even after 5 years. But just imagine how he'd feel knowing he's still remembered and his name is still being honored, his story is still being told, his pictures are still being displayed, and his memorial is still a powerful memory."

Eva Herscowitz and Maya Rao of the Minnesota Star Tribune contributed to this report, which also contains material from the Associated Press.