According to the records obtained by the Judicial Watch from the Florida Department of Agriculture and Consumer Services, the 29-year-old was well trained with a handgun, specifically.
The now-deceased terrorist's security guard and firearms-licensure records from September 2007, show that Mateen underwent 28 hours of classroom and field training to obtain a "Class G" Florida license, Judicial Watch reports.
The documents also show that the deranged killer scored a 231 and 235 on his shooting range tests, using a Smith and Wesson .357 cal. Revolver.
Meanwhile, it was recently revealed that Noor, Mateem's second wife, may have been aware of his violent plans, but didn't report him to police.
Sources told Fox News that federal prosecutors are seeking to charge Noor, 30, as an accessory in the massacre.
As RadarOnline.com previously reported, Mateen opened fire inside Pulse at about 2 a.m. Sunday, killing 49 people, and injuring 53 using an assault rifle.
The crazed killer called 911 during the brutal attack to pledge allegiance to ISIS and even made mention of the Boston Marathon bombing.
Police were able to shoot and kill the security guard after a three hour standoff, during which time Mateen had kept customers trapped as hostages inside the club's bathroom.