This is what we call them instead of nuts with guns, and they are a dreaded modern American cliche. Every time there's a news flash about another mass shooting, we now expect the culprit to be revealed as a "troubled young man."
The recent murders at a Louisiana movie theater were unusual because the gunman was in his 50s. The typical mass killer is much younger.
His family is always stunned by his crime. So are the few friends he has. And in the days following the massacre we always learn more about his loneliness and disillusion, and of course the ludicrous ease with which he was able to arm himself.
The story has become, after so many horrid tragedies, a fill-in-the-blank exercise.
In the hours after 24-year-old Mohammod Abdulazeez killed five U.S. service members in Chattanooga, Tenn., the media frothed with speculation that he was working under the jihadist direction -- or, at least, inspiration -- of ISIS.
Now it appears he was a messed-up kid who drank too much booze, smoked too much weed and spent too much money. Oh, he was also depressed.
FBI agents believe Abdulazeez began exploring Islamic radicalism as his money problems worsened, and his mental condition frayed. Shortly before his shooting spree, he searched the Internet for guidance as to whether martyrdom would absolve a person's sins.
Evidently he found a website or a chat room that seeded this loony brainstorm, and sent him down the path of mass murder. Getting the firepower was, as always, no problem.
Ironically, the day Abdulazeez died after shooting four Marines and a Navy sailor, a jury in Denver was deliberating what to do about another troubled young man.
His name is James Eagan Holmes, age 27. In July 2012 he shot up a packed theater during a "Batman" movie, killing a dozen people and wounding 70 more.
His lawyers insisted Mr. Holmes was insane, which is certainly true. Jurors went ahead and convicted him of all 12 murders, of which he is certainly guilty.
Holmes has Phi Beta Kappa intelligence -- a degree, with honors, in neuroscience -- but was also deeply disturbed from a young age. Some described him as obsessed with the topic of murder, and speaking openly of wanting to kill people.
And kill he did, first loading up on heavy-duty firearms at Gander Mountain and Bass Pro Shops -- two Glock pistols, a Remington "tactical" shotgun and a Smith & Wesson assault-style semiautomatic rifle. The 6,000-plus rounds of ammunition Holmes purchased online.
See, he passed the background checks. So don't look for any blood on the hands of the retailers that armed him.
The gun laws being what they are in this country, the transition from "troubled" to "homicidal" is a breeze. What feeble screening there is can't be counted on to stop young men on bloodbath missions.
Dylann Roof, age 21, shouldn't have been able to buy the .45-caliber handgun he used to murder nine black people in a church inCharleston, S.C., last month.
A federal background check should have flagged him, because Mr. Roof had been arrested on felony drug charges and had admitted to possessing a controlled substance. The FBI has three business days to check if gun buyers have criminal records or drug issues, but the time expired while the agency was trying to gain access to the police report on Mr. Roof.
Because of a loophole in the law, the gun store was able to sell Roof the weapon because the three-day waiting period ended without an FBI response. "We're all sick this happened," FBI director James B. Comey said.
Sick is the word for it. Thousands of ineligible applicants for gun ownership have bought weapons over the counter, thanks to that loophole. Big surprise -- some of those weapons were later used in violent crimes, according to the Justice Department.