Two years – perhaps to the very day – before he murdered five Dallas police officers, Micah Johnson returned from Afghanistan a changed man.

"He was withdrawn, didn't want to talk to people anymore, didn't believe in God anymore," a family friend named Myrtle Booker recalled to the Dallas Morning News.

And Booker was not the only one who described Johnson as withdrawn. The obvious explanation would have been that he was suffering from Post Traumatic Stress Disorder, as have too many returned vets who experienced the horrors of our longest war.

But by numerous reports, Johnson and his Army Reserves engineering unit did not see so much as a moment of combat.

At least part of Johnson’s manifest transformation seems to have been the result not of PTSD, but of what might be termed PTDD, Post Traumatic Disgrace Disorder.

As reported by one of his bunkmates in Afghanistan, Johnson suffered a particular shame.

“We all knew he was a pervert cuz he got caught stealing girls’ panties,” the bunkmate later said in a Facebook post.

Johnson’s military lawyer, Bradford Glendening, says that a female corporal mentioned Victoria’s Secret underthings when she filed a sexual harassment complaint against his client.

The lawyer further reports that the corporal was worried enough to seek an order of protection against Johnson and to recommend that he receive mental health treatment.

All this seems to have transpired shortly after Johnson’s unit was detailed to assist in the preparations for what was described as “a surprise thank you visit” by President Obama to Bagram Air Base on the evening before Memorial Day in 2014.

“To all of you, I’m here on a single mission, and that is to thank you for your extraordinary service.,” Obama told the assembled troops. “I thank you as your Commander-in-Chief because you inspire me…I’m also here representing 300 million Americans who want to say thank you as well. When it comes to supporting you and your families, the American people stand united. We support you. We are proud of you. We stand in awe of your service.”

Nobody was prouder than Johnson’s sister, Nicole Johnson, when she posted a front page newspaper photo of the event on Facebook the next day.

“Happy Memorial Day!...Obama went to visit my big bro in Bagram!”

Her excitement and the president’s praise could have only deepened the shame when he was deemed a panty perv and and shipped home three months early to face sexual harassment charges.

On a date that his lawyer sets as “somewhere around 7 July 2014,” Micah Johnson arrived without the rest of the 284th Engineer Company at the unit’s home base in Seagoville, Texas.

He had joined JROTC (Junior Reserve Officers Training Corps) in high school. He had enlisted in the Army Reserves immediately upon graduating. He had studied at the private Academy of Combat Warrior Arts and he had kept a notebook on tactics. He and the rest of his unit had received a hero’s send-off as they departed for Afghanistan the previous November. And now he was back, just him, having tumbled from awe to awful.

Not two weeks later, on July 17, the whole country was shocked by the video of Eric Garner's death while struggling with New York cops who seemed not even to hear him repeatedly saying, “I can’t breathe!”

Three weeks after that, on August 8, an unarmed Michael Brown was shot to death in an encounter with a cop in Ferguson, Missouri.

Down in Texas, Micah Johnson waited for his lawyer to work out some kind of deal with the Army. Family friend Myrtle Booker noted that along with becoming withdrawn, Johnson had developed an increased interest in firearms, as might befit a onetime panty stealer who found himself lacking.

Also in August, Johnson discovered that a gun stealer had burgled his home in Mesquite and made off with two of them.. Johnson of course called the police and two cops responded, making out a report.

By April of 2015, the Army had surprised even his lawyer by dropping the charges. Johnson received an honorable discharge and remained a member of the ready reserve. He apparently resumed attending the Academy of Combat Warrior Arts on North Greenville Avenue in Richardson.

A month after his severance from the army, he was sitting in a car on North Greenville Avenue, when two Richardson police officers approached. They said they had received a report of suspicious males in the car.

As reported this week by the Dallas Morning News, Johnson told the cops that he had been at a martial arts class. The cops left a few minutes later, but Johnson may well have taken it as harassment because he was a young black male. He had by then begun to take interest in a number of black militant groups, as was reported earlier this week by The Daily Beast.

Johnson likely recalled the encounter last Tuesday and again on Wednesday, when the killing of Alton Sterling by cops in Baton Rouge was followed by the killing of Philando Castile by a cop outside Minneapolis.

Both deaths were captured on video. Castile’s girlfriend recorded the aftermath of that shooting on Facebook live as he was dying beside her and the cop was still pointing his gun and her 4-year-old daughter was in the back seat.

On July 6, the Johnson sister who had been so proud that Obama had visited Bagram when her brother was there went on Facebook to suggest that perhaps the time had come for police to “get a taste of the life we now fear.”

On July 7, if not the second anniversary of his early return in shame from Afghanistan then very close to it, Johnson drove in his mother’s car into Dallas. He took position clad in body armor near the end of the route that had been announced for a march through downtown Dallas to protest these latest killings.

The police in Dallas have made great progress in their relationship with the community. Cops were taking selfies with protesters when Johnson began proving as Lee Harvey Oswald previously had a few blocks away what one man with a rifle can do.

When he was cornered, Johnson told the police that his aim had been to kill white people, especially police officers. He mentioned his military service, but made no reference to the circumstances in which that ended.

On Friday, Obama took time from a NATO meeting in Warsaw to denounce the killings as “vicious, calculated and despicable.” He would be cutting his European trip short in order to visit Dallas next week.

"The demented individual who carried out those attacks in Dallas, he's not more representative of all African-Americans than the shooter in Charleston was representative of white Americans. Or the shooter in Orlando or San Bernardino were representative of Muslim Americans,” Obama said. “They don't speak for us. That's not who we are.”

And those who knew Micah Johnson were saying that he had been a changed man when he returned from Afghanistan. The former bunkmate went on Facebook to note the maniacal absurdity of his onetime comrade’s decision to “avenge the killing of an innocent by killing more innocent (s).”

“He got caught stealing girls’ panties but murdering cops is a different story,” his former bunkmate wrote. “You really never know what someone is capable of until it’s too late.”