The security firm that employed Orlando shooter Omar Mateen concluded that allegations about his inflammatory comments while an armed guard in 2013 were serious enough to transfer him to an unarmed position. But the company, G4S Secure Solutions USA Inc., dropped the matter [and] did not take away his company-issued service weapon. That decision, coupled with the fact that Mateen underwent three separate inquiries by the FBI in 2013 and 2014, raises questions about whether G4S - the U.S. subsidiary of one of the world's largest security firms - properly vetted Mateen in the years before Sunday's mass shooting at the Pulse nightclub. Former G4S security guard Daniel Gilroy ... complained repeatedly about Mateen to supervisors at G4S. They ignored his concerns. Ultimately, Gilroy said, he quit rather than have to face Mateen, who he said threatened him. [A company official] said G4S has so far found no evidence of any other employees making complaints about Mateen, including those who worked at the St. Lucie County Courthouse with him in 2013. FBI Director James Comey said earlier this week that colleagues said Mateen claimed to have family connections to terror groups al Qaeda and Hezbollah, and that he hoped law enforcement would raid his home so he could martyr himself." Those remarks prompted courthouse officials to request Mateen's immediate removal from the St. Lucie County Courthouse, and to make "the appropriate notifications to inform our federal partners," including the FBI.