A Connecticut man spilled details about an international group of Xbox gamers responsible for multiple bomb scares and death threats, including a call to the recently re-opened Sandy Hook Elementary school, according to an affidavit from the FBI.

Matthew Tollis, a 21-year-old from Wethersfield, was arrested on September 3 on charges related to a bomb threat called into the University of Connecticut on April 3.

Through cooperation with investigators, Tollis revealed details about 'swatting' with TeAM CrucifiX or Die, a group of Xbox gamers from the United States and the United Kingdom that used Skype calls to plant bomb threats and intimidate government officials.

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Swatted: Matthew Tollis, 21, admitted to investigators that he participated in bomb threat calls made against universities and schools

'Swatting' is the practice of calling in fake bomb threats to bring SWAT and police response against targeted victims.

According to investigators, Tollis first started following two members of the group on Twitter after being harassed online, believing that following the two would prevent further abuse.

Tollis had been 'pizza bombed,' a prank where huge numbers of pizzas are delivered to a target's home, and 'doxed,' which involves publicly revealing private information like social security numbers and passwords.

Investigators say the first 'swatting' that Tollis participated in was a call to Hebron High School in Carrollton, Texas, in which the caller said a student was in possession of a firearm or bomb.

As SWAT officers arrived at the high school, members of the group tweeted about the bomb threat, according to tweets cached and posted on Pastebin, a plain text sharing site.

On Twitter, declaws took responsibility for the bomb threat and inb4mad posted a screenshot of the Skype call used to make it.

The tweets have since been deleted and the account for declaws has been deactivated.

Tollis told the FBI that he also participated in bomb threats against two New Jersey high schools, the University of Connecticut, Boston University and the Boston Convention and Exhibition Center.

Under threat: Police sent a bomb squad to deal with threats at the University of Connecticut's admissions building on April 3. It later turned out that this was a hoax

All clear: The group Tollis belonged to was linked by investigators to the scare at UConn, which was cleared after no explosives were turned up

Photos from the Hartford Courant show bomb technicians and heavily armed police responding to the threat at UConn.

The Boston Convention and Exhibition Center was hosting an exhibition for gamers with attendance predicted to reach 60,000, when it received a bomb threat.

The caller identified himself as Matt Haag, an Iraqi national 'working for Allah' and said he had planted plastic explosives around the building the night before.

FBI investigators were also able to confirm the group was responsible for other 'swatting' actions, though without the participation of Hollis.

In one, a 14-year-old paid a member of the group $30 through PayPal to call in a threat against a private residence in Willimantic, Connecticut.

Calling via Skype from Scotland, 'Robert' told police he had shot his mother and was still armed.

Investigators say at least three of the members of the group live in the United Kingdom.

Several nearby schools were locked down and a dozen officers responded to the scene, which only deescalated when residents inside spotted police and left the home to speak with them.

After another threat in Connecticut, the Middlesex County District Attorney's Office sent an administrative subpoena to Twitter asking for subscriber information on an account for eviljordie, which Twitter passed on to the user without advanced notice to law enforcement, according to the affidavit.

Using Skype, a caller phoned a paralegal from the District Attorney's Office listed on the subpoena, claiming he was 'ordering a hit man' on her.

Investigators say in August a member of the group called Sandy Hook Elementary, where a 2012 mass shooting claimed the lives of 20 children and 6 children, and said he was coming with an assault rifle to 'kill all your [expletive].'