Whoever got this report did nothing with it, even though Mateen was trying to buy body armor, which should have been enough of a tipoff that something was amiss, especially for someone with a history like Mateen’s. Did the person who got the report fear that acting upon it would bring down charges of “Islamophobia”?

“Gun shop owner claims he reported Omar Mateen BEFORE Orlando massacre and turned him away when he came to buy heavy duty armor and bulk ammo,” by Mia De Graaf, Dailymail.com, June 16, 2016:

A gun store owner reported Orlando shooter Omar Mateen to authorities weeks before he committed the worst mass shooting in US history. Robbie Abell, co-owner of Lotus Gunworks, told the Wall Street Journal Mateen came into the store in South Florida in May and asked for heavy-duty body armor like the kind used by law enforcement. Staff at the store, which does not sell body armor, felt it was a strange demand. After his request was denied, Mateen asked to buy bulk ammunition. Though Lotus does sell ammunition, staff shut down his request and refused to sell him anything else. They subsequently reported the incident to the FBI, Abell said. Mateen had already been investigated by the FBI years before. But even after Abell’s report, the 29-year-old self-radicalized gunman obtained an AR-15 and a semiautomatic pistol from another store in the area, bought stacks of ammunition, then opened fire on Pulse nightclub, where he killed 49 people and wounded 53.

On “self-radicalized,” see here.

The store’s owner Robbie Abell told the Journal: ‘The questions he was asking were not the normal questions a normal person would be asking…He just seemed very odd.’ Abell also said Mateen was speaking to someone on the phone in Arabic and was walking around the store texting. Mateen is of Afghan descent, where the official languages are Pashto and Dari. It is not clear how Abell’s staff deduced he was speaking Arabic.

Probably they assumed it was Arabic when it was something else.