Transcript for Vanessa Guillen’s death renews calls for accountability in the military: Part 2
and major with the reserves, Stephanie Ramos. Reporter: Inside Vanessa Guillen's childhood home the bedroom she shared with her sister Myra, frozen in time. Reporter: For her mother Gloria, those memories now clouded by anger, stemming from what she alleges were the military's missteps in the investigation of her daughter's disappearance and murder. Reporter: Allegations that the army specialist was sexually harassed before she went missing have brought renewed attention to what many call a systemic problem within the military, a culture where sexual harassment and assault are downplayed, leading to underreported cases and lack of accountability. My sister! She's no one's property! She's no sexual trick! The "Me too" movement hasn't occurred in the military. Reporter: The chief prosecutor for the air force served in several high-profile cases of sexual assault. Her story is resonating with the American people and the men and women serving, this can be something that drives the military to finally accept that they're failing at this, and most importantly, get accountability for survivors. Reporter: A Pentagon report released last year shows the amount of reported military sexual assaults increased between 2016 and 2018, from about 14,900 to 20,500 cases. And an estimated one in four service women experienced some sort of sexual harassment in 2018. Both sexual assault and sexual harassment are considered crimes in the military justice system, but it's up to commanders to decide whether or not to bring charges. And so the person who's making that decision to start this prosecution process always knows the person who is being investigated. And they often know the victim as well. So there's this conflict that's built into the system. Reporter: An army official recently told ABC news that in the course of their investigation into Vanessa's disappearance, they found information that pointed to some harassment, but the harassment was not sexual. The Guillen family wants an independent look into what happened to Vanessa. We can't have the fox watch the hen house. Reporter: Her story reaching the nation's capitol. When congresswoman Jackie Speier heard the details of the death and investigation, she was outraged. I think that Vanessa's horrific death and murder has crystallized how bad the situation is. Reporter: She co-wrote this letter, with senator Kiersten Gillibrand, asking for the department of defense to investigate the army's response to Vanessa's death, calling the institution fundamentally broken. What are some concrete actions and legislative policies that can be enacted in the future to prevent sexual harassment and assault from happening in the military? The need to take these cases out of the chain of command so that victims feel that they will have a fair evaluation of their case is critical. There has to be more prosecutions. Reporter: For the last decade, lawmakers have introduced bills to try to change the military's existing reporting system, with little success. Vanessa's familiar shri advocating that an independent agency investigate reports and are working with congress on a bill they plan to unveil later this month. By sharing Vanessa's story, the family hopes other service men and women feel empowered to speak up. Reporter: Vanessa's sisters hope her legacy will live on through meaningful change. I hope that everyone remembers her as a hero. I will remember her as the best big sister. The most wonderful person by my side, and she's still going to be by my side, and I will remember her as the brave young woman, because she literally said I don't care if I die in combat. I die protecting y'all, I die protecting the nation.
This transcript has been automatically generated and may not be 100% accurate.