A former University of Pittsburgh professor facing charges after police said he made threats against other professors at the university called the situation "one big misunderstanding."

According to the criminal complaint, Mark Krangle, 65, of New York, sent emails to current and retired Pitt professors.  In those emails, Krangle said he believes the person behind the bomb threats is someone he has met before, police said.

Attilio Favorini is a current University of Pittsburgh professor who received one of the emails.

"He sent us emails that were very troubling because they seemed to indicate a troubled mind," Favorini said. "He had a 150-page manifesto connected with the Carter presidency being bogus, connected with 911 and the bomb threats at the University of Pittsburgh."

Krangle is a retired Pitt professor who taught at the university in the 1980s.

“I guess our concern was more that (Krangle) might come to our home than he would come to campus,” Favorini said.

According to the criminal complaint, while making the alleged threats, Krangle mentioned the recent shooting at Western Psychiatric Hospital in Oakland.

The complaint said that Krangle wrote, "Don't try to do anything that may involve Western Psych when I get to town.  Things will get much worse if you try to derail me. Support me or perish."

Krangle is charged with harassment and making terroristic threats.

Channel 11's news exchange partners at TribLIVE reported that Krangle was detained at 1:30 p.m. Wednesday at Pittsburgh International Airport by Allegheny County police. He was held until Pitt police arrived to take him into custody, county police Superintendent Charles Moffatt said.

Krangle was taken to an Oakland hospital after complaining of chest pains, officials said.

According to authorities, on Thursday he underwent thallium stress tests while running on a monitored treadmill. The tests will determine if he suffered a heart attack and whether he’s suffering from heart disease. Results are not expected until Friday.

Krangle told officials that everything “is one big misunderstanding.” He also talked about using his Facebook account just so he could be heard, sources said.

Sources said Krangle has told police that he isn't responsible for the Pitt bomb threats, but knows who did. He told police he is willing to tell them who is responsible if they reduce or drop his charges.

Krangle is expected to be arraigned before the weekend.

Meanwhile, more than a dozen more threats were reported at Pitt on Wednesday night and Thursday morning.

A threat was reported at William Pitt Union and Litchfield Towers late Wednesday night.

Early Thursday morning, Channel 11 News received an email that threatened Forbes, Ruskin, Lothrop, Pennsylvania and Bruce halls.

By midmorning, another round of threats were reported at Hillman Library, Frick Fine Arts, David Lawrence, Posvar Hall, William Pitt Union and the University Club.

A threat was also reported at the Cathedral of Learning building Thursday just before 7 p.m.

Nearly 80 threats have been reported at the school since February.

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