TIMELINE: From Vanessa Guillen's disappearance to Fort Hood review findings

Nearly eight months after the disappearance of Army Specialist Vanessa Guillen, U.S. Army officials announced the findings of an independent investigation into Fort Hood. The results led to the firing and suspension of more than a dozen officers and enlisted soldiers at the base, along with policy changes.

Below we take a look at the timeline between Guillen's disappearance and the review findings.

April 22

Army Pfc. Vanessa Guillen is pronounced missing after she was last seen on the morning of April 22 in the parking lot of her Regimental Engineer Squadron Headquarters, 3rd Cavalry Regiment on Fort Hood, Texas, and has not been heard from since.

Her car keys, barracks room key, identification card, and wallet were later found in the armory room where she was working earlier in the day. She was last seen in the parking lot wearing a black t-shirt and purple fitness-type pants.

June 30

Partial human remains were found close to the Leon River in Bell County, an area of interest in the search for missing Fort Hood soldier Vanessa Guillen. 

July 1

A suspect in Guillen's disappearance, later identified as Spc. Aaron David Robinson, her superior, took his own life when law enforcement attempted to make contact with him after he fled from Fort Hood.

Meanwhile, Cecily Aguilar was arrested and charged for assisting Robinson with disposing of Vanessa’s body.

Aguilar faces up to 20 years in prison for conspiracy to tamper with evidence and five years of supervised release if she is found guilty. The charge carries a $250,000 fine.

Cecily Anne Aguilar

DETAILS: One suspect in custody for disappearance of Pfc. Vanessa Guillen, other is dead

Aguilar was previously scheduled to appear in court, but the hearing has been postponed to January.

Also on July 1, Guillen's rank was posthumously advanced to Specialist.

July 6

Officials confirmed on July 6 the remains found near the Leon River belong to Guillen.

The family’s attorney Natalie Khawam says Guillen was murdered, bludgeoned to death by her superior Spc. Robinson.

Her family said Guillen claimed Robinson had sexually assaulted her but army officials said they found no such evidence.

The claims sparked widespread concerns about sexual abuse in the military.

July 30

Secretary of the Army Ryan McCarthy ordered an independent review of the command climate at Fort Hood following Guillen’s slaying.

The purpose of the independent review is to determine whether the command climate and culture at Fort Hood, and the surrounding military community, reflects the Army's values, including safety, respect, inclusiveness, and a commitment to diversity, and workplaces and communities free from sexual harassment.

ARMY: Fort Hood has some of the "highest numbers" of violent acts, sexual harassment cases

August 14

Public memorial set in Houston for slain Spc. Vanessa Guillen.

August 15

Family, friends say goodbye to Spc. Vanessa Guillen in private ceremony and funeral.

September 1

The commander of the U.S. Army's Fort Hood is removed from his post as part of a previously-scheduled change in leadership and will no longer be transferred to Fort Bliss.

Maj. Gen. Scott Efflandt will remain at Fort Hood and continue to serve as deputy commanding general for support. Due to this, the Army will name a new commander for the 1st Armored Division at Fort Bliss in El Paso.

September 8

Congress announced it was launching an investigation into sexual assault, disappearances, deaths and the leadership’s response at Fort Hood after 28 soldiers stationed at the U.S. Army base in Texas died this year.

September 16

Legislation honoring Vanessa Guillen introduced on Capitol Hill. The ' I Am Vanessa Guillen Act of 2020' has bipartisan support. The lead sponsors are U.S. Representatives Jackie Speier (D-CA) and Markwayne Mullin (R-OK). Houston-area Congresswoman Sylvia Garcia (TX-29) and Congressman Pete Olson (TX-22), a Democrat and Republican, are co-sponsors.

RELATED: Advocates push for “I am Vanessa Guillen” bill to assist soldiers and military families

The bill seeks to change how reports of sexual assault and harassment are dealt with in the military and how the military deals with missing service members. It would allow service members to file sexual assault claims to a third party, instead of their chain of command.

An independent prosecutor would be allowed to investigate cases of sexual violence and make sexual harassment and sexual assault a crime with the Uniform Code of Military Justice. Currently, sexual harassment is typically addressed through administrative sanctions.

December 8

The Army announced the findings of an independent panel’s investigation into Fort Hood.

They fired or suspended 14 officers and enlisted soldiers at the base and ordered policy changes to address chronic leadership failures at the base that contributed to a widespread pattern of violence including murder, sexual assaults and harassment.

Two general officers were among those being removed from their jobs, as top Army leaders announced the findings of an independent panel’s investigation into problems at the Texas base.

DETAILS: Officials fire or suspend 14 Fort Hood officers, enlisted soldiers after investigation

The firings and suspensions include Army Maj. Gen. Scott Efflandt, who was left in charge of the base earlier this year when Guillen was killed, as well as Maj. Gen. Jeffery Broadwater, commander of the 1st Cavalry Divisions. The administrative actions are expected to trigger investigations that could lead to a wide range of punishments. Those punishments could go from a simple letter of reprimand to a military discharge.

The base commander, Army Lt. Gen. Pat White, will not face any administrative action. He was deployed to Iraq as the commander there for much of the year.

McCarthy also ordered a new Army policy that changes how commanders deal with missing soldiers, requiring them to list service members as absent-unknown for up to 48 hours and to do everything they can to locate the service members to determine if their absence is voluntary or not before declaring anyone AWOL, or absent without leave.

The Associated Press contributed to this report.