The suspected gunman, Rahmanullah Lakanwal, went on to kill one National Guard member while leaving another wounded.
Donald Trump announced on Thursday evening that Backstrom had died after succumbing to her injuries.
Trump also pledged to cut all federal benefits for noncitizens, revoke citizenship for migrants who threaten the U.S.
President Trump shared the heartbreaking news of the 20-year-old's death during a Thanksgiving evening call with several military units as he reached out to them for the holiday.
The family member said that Lakanwal is married with five young sons, and that he was once wounded while working alongside U.S. troops.
The Biden administration first allowed Lakanwal to enter the U.S. in September 2021 as a refugee through Operation Allies Welcome.
Lizza recently wrote in a blog post about being in a new relationship, though he did not reveal his partner's identity.
This came as the head of the CIA revealed that Lakanwal had previously worked with the agency during his time in Afghanistan.
Like President Trump, Ratcliffe slammed the handling of the evacuation, saying it allowed people who were not properly vetted to enter the United States on temporary visas.
Alisha Marie George, 40, has been charged with attempted rape, forceable sodomy, object rape, forcible sexual abuse and distributing sexual material.
Officials say the suspect fired three shots before guardsmen returned fire, turning the incident into a brief shootout.
Lakanwal himself was shot during the exchange of gunfire and is currently being treated in a hospital, authorities said.
Armed National Guard troops have been stationed in the nation's capital since early August as part of security measures linked to President Donald Trump's crime crackdown.
The Liverpool vs PSV Eindhoven UEFA Champions League match will be played at Anfield, Liverpool, England, on Wednesday, November 26.
The Arsenal vs Bayern Munich UEFA Champions League match will be played at Emirates Stadium, London, England, on Wednesday, November 26.