The attack began without warning or provocation, when a Georgia man stepped off a bus outside the Pentagon on Tuesday, stabbed a police officer and struggled with him, the FBI said.

During the melee, Austin Lanz shot Pentagon officer George Gonzalez with the officer’s service weapon, before turning the gun on himself, the FBI said. Other Pentagon officers engaged Lanz and he was killed. The officer later died.

The account released Wednesday was the first detailed description of the encounter, which prompted a lockdown of the Pentagon and drew a massive response from police and fire agencies. Officials said a bystander also was injured.

An FBI spokeswoman said the agency was still probing the motive in the case as the investigation continues, but Lanz had been ordered to undergo a mental health evaluation by a judge in Georgia and had allegedly acted violently and erratically in recent months, court and police records show.

Lanz, 27, was most recently a resident of Acworth, Ga., the FBI said. He had tried to enlist in the Marines but did not make it through boot camp, a spokesman said. He also faced a number of charges that were pending at the time of the attack outside the Pentagon. His family did not respond to requests for comment.

Officials at the Pentagon Force Protection Agency on Wednesday identified the slain police officer as Gonzalez, 37. He had been promoted twice and attained the rank of senior officer in 2020.

Officials said Gonzalez had served with the U.S. Army and was awarded the Army Commendation Medal for his service in Iraq. He also had stints in the Transportation Security Administration and the Federal Bureau of Prisons.

Gonzalez’s family released a statement Wednesday saying he had an infectious personality, a big heart and “was fiercely loved by his family and friends.”

“We are heartbroken over the death of our son and brother, but we are so very very proud of the life he lived,” the statement read. “George devoted his life to serving his country; first in the military, and then, as a law enforcement officer, he continued to serve by protecting service members and citizens of this country.”

Pentagon Force Protection Agency Chief Woodrow Kusse said Tuesday that the officer was attacked on the Metro bus platform shortly before 10:40 a.m., shots were fired, and there were “several casualties.” He said authorities were not seeking additional suspects.

The FBI said Wednesday that the injured bystander was treated at a hospital and released.

Gonzalez, a Brooklyn native, joined the Pentagon force in 2018. In a statement, officials with the force said he took to heart the mission of “protecting those who protect our nation.”

Gonzalez was a “die-hard Yankees fan” and graduated from New York City’s Canarsie High School. He later worked at the Bureau of Prisons and the TSA, rising to the rank of lead transportation security officer before landing at the Pentagon’s police agency.

In a statement, Pentagon police officials described him as gregarious and said he was “well-liked and respected by his fellow officers.”

Gonzalez also served in Army artillery as a cannon crew member, with time on active duty from April 2003 to November 2005, and in the Army Reserve from November 2005 to March 2011. He left the service as a sergeant. He was deployed to Iraq from August 2004 to July 2005, said Lt. Col. Gabriel Ramirez, an Army spokesman.

While deployed in Iraq, Gonzalez was a member of 2nd Battalion, 17th Field Artillery Regiment, Ramirez said.

Gonzalez also received a Korea Defense Service Medal, indicating that in addition to his time in Iraq, he served a stint in South Korea.

Lanz’s interaction with the military was brief.

On Tuesday evening, the U.S. Marine Corps released a statement saying Lanz sought to join the Marines on Oct. 9, 2012, but was “administratively separated on Nov. 2, 2012 and never earned the title Marine.”

It was not immediately clear what Lanz did in the following years.

In April, Lanz was arrested for allegedly breaking into a neighbor’s home in Georgia, according to a police report. The neighbor’s surveillance camera captured Lanz walking through the home holding a crow bar, the report states.

The neighbor told investigators that he was planning on moving because he had had numerous encounters with Lanz over the previous year and did not feel safe, according to the police report. 

In one incident, the neighbor told investigators that surveillance video showed Lanz placing pornographic images and sexual notes in his mailbox, according to the report. On another occasion, police were called after a complaint that Lanz had placed a large cardboard sign on the neighbor’s front porch that read, “I’m tired of wondering.”

On the day of his trespassing arrest in April, Lanz was accused of assaulting two Cobb County sheriff’s deputies at the local jail. He also was charged with criminal damage, riot in a penal institution, obstructing law enforcement and making terroristic threats.

The Cobb County Sheriff’s Office in Georgia confirmed that Lanz was in custody in April 2021, but it referred all other questions about the incident at the jail to the FBI. The office released a redacted incident report that offered scant details about what happened.

In May, a judge granted Lanz cash bond in the cases, and some of the charges were dropped. As a condition of his release, Lanz was ordered to stay away from drugs and alcohol and not possess firearms. 

He also was ordered to undergo mental health and substance abuse evaluations within 30 days and not have contact with three specified individuals, online court records indicate. Those people did not respond to requests for comment.

It was not clear from online records whether Lanz had undergone the evaluations, and a spokeswoman for the Cobb County district attorney’s office said she could not answer most questions about the case. The charges against Lanz remained pending at the time of the attack at the Pentagon on Tuesday.

Lanz’s attorney in the cases did not return calls seeking comment.

On Wednesday, Gerald G. Neill Jr., president of the D.C. Fraternal Order of Police Lodge #1, said Gonzalez’s slaying and other recent violent incidents that have involved law enforcement officers in the region are concerning.

“A lot of people felt it was a safe police department,” Neill said of the Pentagon police force. “We tell them it’s not. You wear a uniform that says ‘police.’ It’s not safe.”

Gonzalez was not a member of the D.C. FOP, which has about 8,000 members.

Neill said many of his group’s members are worried and feeling stressed.

“There’s a dehumanization of police across the country, and that’s hurt these officers,” Neill said.

Defense Secretary Lloyd Austin also issued condolences in a statement. He ordered flags at the Pentagon to half-staff to honor the slain officer.

“This fallen officer died in the line of duty, helping protect the tens of thousands of people who work in — and who visit — the Pentagon on a daily basis,” Austin said. “He and his fellow officers are members of the Pentagon family, and known to us all as professional, skilled and brave.”

The violence occurred at the Pentagon Transit Center, which is on the east side of the Pentagon and is the largest transit hub in Northern Virginia, according to the Defense Department.

Metro said it plans to reopen the Pentagon Metro station and Pentagon Transit Center on Thursday morning. The stations had been closed since Tuesday morning.

Devlin Barrett, Justin George, Tom Jackman, Julie Tate, Emily Davies and Martin Weil contributed to this report.