Bobby Brown I'm Gonna Nail Whoever Took Deathbed Pic

7/5/2015 3:23 PM PDT

Bobby Brown is on a mission to expose the person responsible for taking a photo of Bobbi Kristina in hospice.

We got Bobby at LAX and asked if he agreed with his sister's rage-filled rant about the photo -- and he made it clear ... the Brown family's standing together on this.

As we first reported ... someone is actually shopping the pic around to websites and magazines.

Watch this video -- it's clear the the whole ordeal is weighing heavily on Bobby, but he's still pushing for "justice."