Suspect in UT Austin mass shooting threat arrested in Crosby

University of Texas at Austin police have arrested a man who is accused of threatening to shoot at least 200 people at the school.

School police and Harris County deputies arrested Sean Evan Haddon, 23, in Crosby at 9 a.m. Sunday. He has been charged with making a terroristic threat, a third-degree felony, police said in a Facebook post.

Haddon also told dispatchers that he had placed a bomb in the police department, but that claim was false, police said.

The arrest comes just weeks after police caught Mark Anthony Conditt, the Austin "serial bomber." Conditt was accused of killing two people and injured several others in a series of March bombings before detonating a bomb on himself.

"Recognizing that the community was absolutely terrorized during the bombing events that occurred in the city, it was really important for us to get on top of this as quickly as possible," UT Police Department Chief David Carter said.

UT officials received a total of four threatening calls related to Sunday's arrest, and each was believed to be from Haddon, Carter said.

The University of Texas Police Department first got a call on April 7 from a person who said he put a pipe bomb in the lobby of the campus police department. The caller demanded payment in Bitcoin and the dispatcher's participation in sexual acts, or else he would blow up the building, according to the police department.

The call disconnected, and another call came in from someone who sounded like the previous caller. He again threatened to blow up the building, police said.

UTPD searched the police department building and did not find anything suspicious.

Police got another call April 12 from someone who made threats of shooting the dispatcher.

And most recently, UTPD received a final call on April 13 from a supervisor at the UT Human Resource Service Center. The supervisor said they were on the phone with a man who wanted to shoot up the university, or "at least 200 people," police said.

A UTPD officer took over the call, and the person on the line said he would "kill the first person he sees," police said.

Police tracked the phone to a home in Crosby and arrested Haddon.

Some firearms were seized, but Haddon didn't have a cache of weapons or ammunition, Carter said.

Haddon has no affiliation with UT Austin, and UT police have never dealt with him before, said Noelle Schrader, UTPD director of campus safety communications.

It is not known why Haddon singled out the campus, Carter said.

UT President Greg Fenves thanked police on Sunday for making the arrest.

"Outstanding police work by @UTAustinPolice assessing calls and tracking down this suspect," Fenves tweeted. "Thanks for all you do to keep our campus and community safe."

Police investigated each call and determined that there was no active threat that would have sparked a need to notify the campus, according to the department. After each call, police were able to determine that there was no immediate threat and that the caller wasn't in the area, Carter said.

"If we didn’t know where he was, that could have certainly triggered some action in terms of putting out information," Carter said.

A Travis County judge issued two search warrants for Haddon and set his bond at $300,000, Carter said. The threats are still under investigation.