Crime scene tape is seen in front of the library at Florida State University, in Tallahassee, Florida, Nov 20, 2014. Three students were shot and wounded when a gunman opened fire inside the main Florida State University library early on Thursday, and campus police shot the suspect dead, officials said. [Photo/Agencies]

TALLAHASSEE, Fla. - Brandishing a semi-automatic handgun and carrying extra ammunition in his pockets, a Florida State University graduate opened fire early on Thursday at the school's main library, wounding two students and an employee as hundreds were studying for exams.

The shooter, identified by authorities as Myron May, 31, was fatally shot by police near the entrance to Florida State's Strozier Library, the latest in a string of shootings on US campuses. One victim was critically wounded.

Authorities said they found journals and videos produced by May in which he expressed fears that government agencies were targeting him.

"Mr. May was in a state of crisis," Michael DeLeo, the police chief in Tallahassee, told a news conference.

A 2005 Florida State graduate, May received his law degree from Texas Tech University in 2009 and had moved back to Florida about three weeks ago, DeLeo said.

He recently quit his job and broke up with his girlfriend, according to police reports in Las Cruces, New Mexico, where he was living. He told authorities he was hearing voices and thought he was being watched.

Florida police said they did not know why he chose this day to open fire. The initial call about a gunman came at 12:25 am local time, police said. By 12:27 am, May had been shot down outside the library.

Thirty rounds were fired during the incident, including shots by law officers and by May, who used a .380 caliber handgun, authorities said.

Authorities did not identify the man who was critically wounded or another man treated at the scene for a graze wound. A third victim, Nathan Scott, was in good condition after being shot in the leg and recovering at Tallahassee Memorial HealthCare hospital, a hospital spokeswoman said.

Atlanta's WSB-TV said eight of May's friends were expecting packages to arrive from him on Friday. They have been told to call police when the parcels arrive, the ABC affiliate reported.

Campus security was raised and classes were canceled on Thursday. University President John Thrasher said normal operations would resume on Friday at the campus of about 40,000 students.

The shooting came amid heightened concerns about safety at US schools and a long-running debate about gun control.

"Another campus shooting. Yet we still haven't started even a dialogue on keeping guns from criminals and the mentally ill," Democratic US Senator Bill Nelson of Florida said on his Twitter page.