Play video content EXCLUSIVE TMZ.com

The Ft. Lauderdale Airport shooter walked casually through baggage claim before suddenly pulling his gun out and wreaking havoc.

TMZ has obtained video of the shooting ... we are only showing the seconds leading up to the first shots fired and the panic that ensued.

You see the shooter, 26-year-old Esteban Santiago, with a 9 mm handgun tucked inside his waistband, and then pulling it out and beginning to shoot.