A spokeswoman for the U.S. Postal Inspection Service said the packages sent by Myron May have been collected by investigators. The service determined the contents weren't hazardous.
"The contents of the mailings are being transferred to the FBI for additional analysis," Lori J. McAllister said.
Joe Paul of Washington, D.C. said that a postal inspector called to let him know he had received a package from May. He was told there was a long letter and a jump drive inside, Paul said.
Paul's package from May, a 2005 FSU graduate, appears to be in a standard Priority Mail envelope, based on a photograph Paul said May sent him as confirmation of its mailing.
The envelope was scheduled to arrive Friday, Paul said. But he is traveling, and the FBI now has the envelope.
Paul told CNN on Friday that May -- who was killed by police during Thursday's shootings -- had asked him and several others for their mailing addresses in a November 15 Facebook message.
"I really thought it was a wedding invitation or something," he said. "On Wednesday at 9:53 (p.m.), he said y'all should receive your packages Friday. Then I went to sleep and woke up to tragedy."
Agents from the FBI's Houston office were in possession of one package, Special Agent Shauna Dunlap said. Its contents aren't being made public, she said.
Dunlap said Friday that the Houston package may first go to a lab for analysis, but will eventually go to the Tallahassee Police Department, the lead agency in the investigation of Thursday's shooting.
Victim released from hospital
May, 31, fired shots in FSU's Strozier Library
around 12:30 a.m. Thursday, wounding three of the 300 or 400 students inside -- one of them critically, police said.
Cell phone video posted online
captured the moments after the shooting, in which students huddled inside the packed library.
Officers who encountered May outside shot him when he refused to drop his weapon, police say.
"The suspect did not comply with the commands and actually shot at one of the officers," Tallahassee police spokesman David Northway said. "They returned fire, and the subject was killed."
Two students wounded in the shooting were hospitalized at Tallahassee Memorial HealthCare, according to the hospital. Nathan Scott, who was shot in the leg, was discharged Friday.
The other patient was initially was listed in critical condition. The hospital has not updated the victim's condition.
The third shooting victim, who was grazed by a bullet, was treated at the scene and not hospitalized.
'Fears of being targeted'
Tallahassee police declined to comment on the packages or what they contain.
Police Chief Michael DeLeo, did however, tell reporters Thursday that May had a journal and videos in which he "expressed fears of being targeted and that he wanted to bring attention to this issue of targeting."
A preliminary review of these documents and videos demonstrates "that Mr. May was in a state of crisis," DeLeo said.
In September, May called police in Las Cruces, New Mexico, convinced that someone had placed cameras in his apartment and complaining that he was hearing voices through the walls, according to an incident report provided by the department.
A month later, his ex-girlfriend called police, saying May believed "the police are after him and are bugging his phone and car," according to another incident report.
'He did his job with distinction'
May worked briefly as a felony prosecutor in Dona Ana, New Mexico, District Attorney Mark D'Antonio said.
"He did his job with distinction and honor," D'Antonio said.
He abruptly resigned on October 16 in a letter that made no mention of any troubles, D'Antonio said.
Paul, who knew May from their days at FSU and had kept in touch over Facebook, said he doesn't think May would want to hurt him. He hopes that what's inside the package will shed some light on what happened.
"I hope it's the answer to why," he said.