In a statement released on Tuesday, the Army's investigation concluded that Guillen's death was "in the line of duty."
"This determination establishes that the Guillen family is entitled to a variety of Army benefits for Vanessa's service to our nation," read the statement.
Typically, these benefits include money to help the family with expenses, the service member's Group Life Insurance along with final pay and allowances.
The Army conducts a line of duty determination for all soldier deaths.
Investigators said Guillen was bludgeoned to death at Fort Hood by Spc. Aaron Robinson, who killed himself on July 1 as police were trying to take him into custody.
Guillen's family has said Robinson had sexually harassed her, but the Army has said there is no evidence supporting the claim.
Last month, friends and family of Guillen celebrated what would have been her 21st birthday, and they're still fighting for justice for the Army specialist.
"Five months have passed and yet still no accountability or justice for us," Vanessa's sister Lupe Guillen said at the time.
Meanwhile, a bill in honor of Guillen is being deliberated in Washington, D.C.
If passed, the #IAmVanessaGuillen bill would allow active duty members to file sexual harassment and assault claims to a third party.
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The Associated Press contributed to this report.