How a fantasy football feud turned into a hoax mass shooting report — and a guilty plea

A Philadelphia man admitted to reporting a hoax mass shooting and then a bomb threat in retaliation over a fantasy football argument, authorities said Wednesday.

Matthew Gabriel, 25, could face up to five years behind bars after he pleaded guilty to two counts of interstate and foreign communication of a threat to injure, the U.S. States Attorney's Office in Philadelphia said.

But it's more likely that Gabriel, a house painter, will get 15 months of home confinement when he's sentenced in January, according to the man's defense attorney Lonny Fish.

The lawyer said he remains baffled by his client’s actions.

“I don’t know what he was thinking,” Fish told NBC News on Thursday. “It was definitely not smart.”

Gabriel had "an online disagreement with a member of his fantasy football chat group" before that victim, a student at the University of Iowa, traveled to Norway on Aug. 3 last year for a study abroad program.

The disgruntled fantasy player then submitted an online tip to the Norwegian Police Security Service — the Politiets Sikkerhetstjeneste (PST) — claiming that the foreign student was going to commit a mass shooting.

"On August 15th a man named (the victim) is headed around oslo and has a shooting planned with multiple people on his side involved. they plan to take as many as they can at a concert and then head to a department store," Gabriel wrote, according to prosecutors.

"I don’t know any more people then that, I just can’t have random people dying on my conscience. he plans to arrive there unarmed spend a couple days normal and then execute the attack. please be ready. he is around a 5 foot 7 red head coming from America, on the 10th or 11th I believe. he should have weapons with him. please be careful."

Norwegian authorities spent 900 man hour investigating and disproving that threat, Fish said.

Then on March 22 of this year, Gabriel — aware he was under investigation for the Norway hoax — emailed the University of Iowa telling school officials there that that same victim was going to set off a bomb on campus, according to prosecutors.

That email "contained a screenshot from the fantasy football group of a message that stated 'Hello University of Iowa a man named (victim) told me he was gonna blow up the school,' ” the U.S. Attorney said.

"Gabriel knew that the victim was not going to blow up the university and that the message had been sent in jest by another member of the fantasy football group regarding Gabriel’s prior threat," according to prosecutors.

“While already being prosecuted for one hoax threat spurred by, of all things, his fantasy football league, Matthew Gabriel inexplicably decided to send another,” U.S. Attorney Jacqueline Romero said. “His actions were extremely disruptive and consumed significant law enforcement resources on two continents, diverting them from actual incidents and investigations."

Fish, the defense attorney, said he's grateful the government agreed to house arrest.

"Frankly, he's very fortunate to have this opportunity," Fish said. "Most people would be going to prison. This is not the type of thing you get house arrest for. This is the type of thing, you (often) go to prison."

Court documents did not outline the nature of Gabriel's beef with the University of Iowa student and Fish declined to reveal those details.

"The guy (victim) didn't deserve it, I can tell you that," Fish said. "He (Gabriel) was apologetic to the victim, very apologetic. He (Gabriel) was immature and he (the victim) didn't deserve it. There was no justification for it."