(NewsNation) — Sen. Chuck Grassley, R-Iowa, is calling on the military to investigate the death of U.S. Army Pfc. Denisha Montgomery after NewsNation’s coverage disclosed new details about the events leading up to her death.

Grassley has asked for answers by Dec. 20.

Montgomery’s family believes she was murdered while on deployment. A military report on her death said Montgomery committed suicide, but reports obtained later contradicted that claim.

Tune in to NewsNation’s “Rush Hour” at 6 p.m. ET for Rich McHugh’s full report on Grassley’s call for an investigation into Montgomery’s death.

Before her death, 27-year-old Montgomery told her family she had been assaulted by fellow soldiers while serving in Germany. On a video call, which she asked her family to record, she reportedly had bruises and open wounds.

Montgomery said she went off base with a group of military police to visit a water park. On the way back, she said they assaulted and choked her. Montgomery told her family she intended to report the incident.

Twenty-one days later, Montgomery was found dead in her barracks. The Army told her family she had committed suicide. Later, a report was uncovered that showed the Army still had her category of death listed as “pending” and the cause still under determination.

In his letter to Army leadership Tuesday, Grassley asked for the full file of the investigation and called out specific incidents that he said needed clarification, including allegations that Montgomery was told she would be disciplined for fighting back against her assailants if she reported the assault.

Grassley also asked the Army to clarify whether Montgomery successfully reported the assault prior to her death and if an investigation was conducted.

In a statement to NewsNation, the Army wrote: “The Army has endeavored to provide all possible information to both Spc. Denisha Montgomery’s family and Congress throughout the ongoing law enforcement investigation into her death and will provide thorough overviews to both once complete.”

Grassley is a co-sponsor of the Military Justice Improvement and Increasing Prevention Act, which he is co-sponsoring with Sen. Kirsten Gillibrand, D-N.Y. First introduced in 2013, the act would move the decision to prosecute serious crimes, including sexual assault, from the chain of command to a group of independent military prosecutors.

Montgomery’s case highlighted the violence faced by female service members. In the 2020 fiscal year, the U.S. Department of Defense reported 6,290 allegations of sexual assault lodged by service members reporting incidents that occurred during military service.

In January 2022, President Joe Biden signed legislation making sexual harassment a violation of the Uniform Code of Military Justice. The order also allows soldiers who are assaulted to report it to a third party instead of their command.