The sister of Marcus-David Peters, who was shot and killed by a Richmond Police officer in 2018 during what has been described as a mental health crisis, has formally announced her candidacy for Virginia’s gubernatorial race.

Princess Blanding, 38, said Tuesday that she is running under the banner of the newly formed Liberation Party.

Mr. Peters, a 24-year-old high school biology teacher, had struck several cars with his vehicle, then ran onto Interstate 95 naked and unarmed during rush-hour traffic on May 14, 2018. According to several reports and police body camera video, Mr. Peters then ran toward the officer, shouting and threatening to kill him. The officer fired a Taser at Mr. Peters, which appeared to have no effect, and then shot Mr. Peters with his service weapon.

The Richmond commonwealth’s attorney at the time, Michael N. Herring, found that the officer was justified in firing his weapon. Another review of the case by current Richmond Commonwealth’s Attorney Colette W. McEachin and released in November reached the same conclusion.

Since her brother’s death, Ms. Blanding has become an activist on police reform and social justice issues. She lobbied for a law to dispatch mental health providers alongside police to help people in crisis situations. During a ceremonial signing of the law earlier in December, she blasted state lawmakers and Gov. Ralph S. Northam for what she called a “watered down, ineffective” law.

Ms. Blanding, a former assistant principal at Essex High School in Tappahannock where her brother taught, said the mission of the Liberation Party and her platform is “to build a diverse, inclusive and liberated Virginia for all.”

She said her campaign will focus on issues to include criminal justice, racial justice, education, housing and health care.

Demonstrators protesting police brutality and racial injustice following George Floyd’s death in late May at the hands of Minneapolis Police unofficially renamed the grassy area around the Lee statue on Monument Avenue to Marcus-David Peters Circle in tribute to Mr. Peters.