DALLAS — The man who the Dallas police say killed five officers in a barrage of bullets on Thursday was a troubled Army reservist who left Afghanistan under a cloud of sexual harassment charges made by a fellow soldier who sought an order of protection against him and said he needed mental health counseling.

Micah Xavier Johnson, 25, served in the Army Reserve from 2009 to 2015, attaining the rank of private first class, according to Army records.

He was deployed to Afghanistan in November 2013 with the 420th Engineer Brigade, based in Seagoville, Texas. His job specialty was as a mason and carpenter. Nothing in his records suggests that he saw combat, or was injured.

While he was in Afghanistan, a female soldier in Johnson’s unit accused him of sexual harassment, according to Bradford Glendening, the military lawyer assigned to represent Johnson when he returned to Texas.

Quoting from Johnson’s file, which was dated May 2014, Glendening said that Johnson’s accuser recommended that he receive “mental help.’’ She also requested “a protective order against Pfc. Johnson pertaining to myself, my family, home, restaurant and any other place of residence I may reside at.’’

According to Glendening, the Army initiated proceedings to kick Johnson out of the military for what is known as an other than honorable discharge.

“They didn’t like him, that was very clear from talking to his commander,’’ Glendening said.

On Glendening’s advice, Johnson waived his right to a hearing in exchange for a lesser charge.

Johnson’s Facebook profile page, which has been taken down, paid homage to black pride, featuring images of a raised fist and pictures of the red, black, and green Pan-African flag. Both have been symbols of nonviolent black empowerment for decades, and have also been co-opted by violent extremist groups with racist views.

Johnson also “liked’’ two groups that could point to his ideological views. One is the New Black Panther Party, which was founded in Dallas, according to the Southern Poverty Law Center.

The Anti-Defamation League categorizes the organization as the largest anti-Semitic and racist black militant group in the United States. The other group is the African-American Defense League, run by a man named Mauricelm-lei Millere.

“Millere is known for calling for violence against police specifically, on a regular basis,’’ said Oren Segal, the director of the Anti-Defamation League’s Center on Extremism. “Usually after a high profile police-related shooting he takes to social media to encourage violence against police.’’

Johnson’s Facebook page also included a post from April of a picture of himself with Richard Griffin of the rap group Public Enemy. Griffin, known as Professor Griff, made headlines in the 1980s for anti-Semitic comments and has been associated with a radical strain of Afrocentrism.

Police said that people they interviewed have described Johnson as a “loner.’’

After Johnson was identified as the gunman, his younger sister, Nicole, expressed anguish on her Facebook page: “I keep saying [it’s] not true . . . my eyes hurt from crying.’’

Johnson was killed by a remote-controlled explosive after a lengthy standoff with the police. Negotiators tried to get him to surrender, while he was cornered on the second floor of a parking garage, according to the Dallas police chief, David O. Brown.

Johnson “told our negotiators that the end is coming and he’s going to hurt and kill more of us, meaning law enforcement, and that there are bombs all over the place in this garage and downtown,’’ Brown said Friday.

According to Brown, Johnson also told negotiators that he was “upset about Black Lives Matter,’’ as well as the recent police shootings of black men.

He had no criminal record, the Dallas police said. But the department said in a news release the police searched his house in Mesquite, a Dallas suburb.

“During the search of the suspect’s home, detectives found bomb-making materials, ballistic vests, rifles, ammunition, and a personal journal of combat tactics,’’ it said.

There are no immediate indications that the attack was related to terrorism, international or domestic, officials said.

Johnson graduated in 2009 from John Horn High School, where he was involved in the JROTC program, said Allison Lewallyn, a spokeswoman for the Mesquite Independent School District, The Washington Post reported.

A friend of Johnson, Israel Cooper, said Johnson ‘‘wasn’t one of those, ‘white cops, black cops’?’’ kind of people.

Cooper said that when he heard Johnson was a suspect he couldn’t believe it because Johnson wasn’t ‘‘a violent or rough dude.’’