Police identified the officer as Gunther Hashida.
They say he was found dead at his home on Thursday, July 29.
"We are grieving as a Department as our thoughts and prayers are with Officer Hashida’s family and friends," a police spokesperson said.
Hashida joined the department in May 2003.
Five people died as a result of the riot at the U.S. Capitol – including a Capitol police officer.
Capitol police officer Howard Liebengood took his own life days after the incident, along with D.C. police officer Jeffrey Smith.
If you or a loved one is feeling distressed, call the National Suicide Prevention Lifeline. The crisis center provides free and confidential emotional support 24 hours a day, 7 days a week to civilians and veterans. Call the National Suicide Prevention Lifeline at 1-800-273-8255 (tel:18002738255). Or text HOME to 741-741 (Crisis Text Line)
Hashida's wife posted a statement on her Facebook page, along with a photo of them together.
Hashida's wife, Romelia, posted this on her Facebook page: