A third police officer who defended the US Capitol during the 6 January insurrection by extremist supporters of Donald Trump has taken his own life, Washington DC’s Metropolitan police department confirmed on Monday.

Officer Gunther Hashida, who was assigned to the emergency response team within the special operations department, was found dead at home on 29 July, the department said.

Hashida, 44, joined the force in May 2003 and was among those who responded to the Capitol attack, spokesperson Brianna Burch confirmed to the Guardian.

“We are grieving as a department and our thoughts and prayers are with Officer Hashida’s family and friends,” Burch said.

Hashida is survived by his wife, Romelia, and three children, his sister and other members of a “wonderful family”, according to an online fundraising campaign established in his memory.

The death of Hashida is the third known instance of a suicide by law enforcement officers related to the 6 January insurrection, when a mob of Trump supporters stormed the Capitol in a violent attempt to stop the certification of Biden’s election win.

The attempt failed and Biden’s victory over Trump from the 2020 election was certified by Congress in the early hours of the following morning.

But the attack on the Capitol, which lasted several hours, involved rioters attacking outnumbered officers to break into the building in a failed effort to hunt down lawmakers, including then-vice president Mike Pence.

Trump was impeached, for an unprecedented second time, on the charge of inciting the insurrection, and acquitted in February by the Senate.

Officer Jeffrey Smith, a 12-year veteran of the force, and Officer Howard Liebengood, a 16-year Capitol police veteran, also responded to the 6 January attack and later died by suicide.

Hashida’s death comes a week after officers testified to a House select committee about their harrowing experiences defending Congress.

Almost 600 people have been criminally charged for their part in the events.

• In the US, the National Suicide Prevention Lifeline is at 800-273-8255 and online chat is also available. You can also text HOME to 741741 to connect with a crisis text line counselor. In the UK and Ireland, Samaritans can be contacted on 116 123 or email jo@samaritans.org or jo@samaritans.ie. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at www.befrienders.org