LSU Police Capt. Cory Lalonde said officers arrested William Bouvay Jr., 42, of Baton Rouge late Tuesday night after an investigation by multiple law enforcement agencies.
Lalonde said Bouvay was not an LSU student and appeared to have no connection to the campus. He did not know what the suspect's motive might have been.
Investigators don't think Bouvay is connected to threats made last week at college campuses in Texas, North Dakota and Ohio.
"We don't believe at this point that there is any connection to the bomb threats at other universities," Lalonde said.
Lalonde said police tracked Bouvay down after determining the 911 call received Monday at 10:32 a.m. CDT came from a deactivated cellphone that could only make emergency calls.
Lalonde said investigators were able to pinpoint the location of the cell phone on Tuesday and searched homes in the Baton Rouge neighborhood before identifying Bouvay as a suspect.
"Upon questioning, he admitted to making the phone call," Lalonde said, adding that Bouvay has been cooperative.
The threat set into motion a massive evacuation of the sprawling campus that sparked traffic jams as thousands left.
The caller didn't specify where on campus bombs might be planted, so bomb-squad officers with explosives-sniffing dogs were called in to search all buildings.
As with the threats made last week at the University of Texas, North Dakota State University and Hiram College, the search failed to turn up explosives.
Lalonde said authorities believe Bouvay is the person who called the East Baton Rouge Parish 911 Center, claiming multiple bombs would detonate on campus within two hours.
According to police documents, the caller said, "Yes, I planted three bombs at LSU's school campus," and added, "This is not a joke." Authorities believe he was the only person involved in the Baton Rouge scare and Lalonde said they don't anticipate making any further arrests.
Authorities said he will be charged with communicating false information of a planned bombing and could face other charges.
Moore said Bouvay does not have a lawyer yet. Calls to a listing for Bouvay in Baton Rouge rang unanswered.
The university was upbeat before Monday's threat after LSU rose to No. 2 in The Associated Press college football poll with a win over Idaho on Saturday.
Officials believe a majority of the university's 30,000 students, professors and employees were on campus when the threat was made.
Students were allowed to return to dormitories late Monday night and classes resumed on Tuesday. An estimated 6,000 students live on campus.
Interim LSU President William Jenkins said he's pleased at how swiftly a suspect was identified and apprehended, but doesn't know why Bouvay targeted LSU.
"I'm very proud of our resilience, as disruptive and as harmful as this episode was. We're back at work and once again we're a productive, thriving university," he said.