Barriss' digital footprint suggests he was familiar with swatting.

One of his Twitter handles was @SWAuTistic. The Twitter account has been suspended but CNN was able to find a cached copy of the profile that had multiple references to swatting. In a December 22 tweet, he said he was "thinking about swatting" the FBI headquarters.

Two people who knew Barriss through the gaming and online community spoke to CNN on condition of anonymity for fear of retaliation in that community. One of them communicated with him after the Wichita shooting. CNN reviewed some of their messages.

"I was in shock so I messaged him asking him why he'd do that," the friend told CNN. "He said it was stupid and he shouldn't have done it, but I didn't care. He's a grown man who's done this stuff before."

The other friend said the Wichita call stemmed from an argument among two gamers that didn't involve Barriss or Finch. One of the gamers contacted Barriss and asked him to swat the other gamer, the friend told CNN. Barriss "was known in the gaming community for doing stuff like that," the friend said when asked why Barriss would be contacted about swatting.

Barriss was arrested in 2015 for calling in fake bomb threats to CNN affiliate KABC, Glendale Police Sergeant Victor Jackson said. He received a two-year sentence.

"After he got out of jail, he said he did it for attention and to be on the news but that was it. He also said he regretted it and wouldn't do it (again) but that was obviously a lie," one of the anonymous friends said of the 2015 arrest. "I think he feels powerful being able to do stupid stuff like that."

A fake hostage situation call

It's not clear why Barriss allegedly received the Wichita address. The victim's mother told KAKE that her son did not play video games, suggesting a possible case of mistaken identity.

In the Wichita prank call, the caller said someone had an argument with their mother; that the father was accidentally shot; and that a brother, a sister and the mother were held hostage, Wichita police Deputy Chief Troy Livingston said.

"We learned through that call that the father was deceased, shot in the head. So that's the information we were working off of," Livingston said. "Our officers came here preparing for a hostage situation. Several got in position. A male came to the front door, and one of our officers discharged his weapon."

Police said they shot Finch after he moved his hands to his waistline, Livingston said. He was taken to a hospital, where he died.

Livingston said Finch was not armed and nobody was found dead at the home. He called the shooting "tragic and senseless."

"The irresponsible actions of a prankster put people's lives at risk," he said Friday. "The incident is a nightmare for everyone involved, including the family and our police department. Due to the actions of a prankster, we have an innocent victim. If the false police call had not been made, we would not have been there."

But the victim's mother said police shared the blame. "The cops are trying to make this go away and it's not gonna go away. People aren't gonna let it," Lisa Finch told KAKE.

Very simple to pull off

The dangerous scams are usually carried out in one of two ways, and both are incredibly simple.

One is called caller ID spoofing. The quick and free trick, using websites and apps, makes a call appear to the 911 operator as though it is coming from inside someone's house.

A second swatting method sidesteps the traditional phone system altogether. Some swatters use a teletypewriter (TTY) relay -- a phone system created for people who are deaf -- to place 911 calls. The TTY system is appealing to swatters because the Federal Communications Commission requires relay services to keep TTY calls, and callers, confidential.

Even if relay operators believe a 911 call may be a hoax, they're generally prohibited from intervening -- calls must be relayed verbatim.