arabia helped the 9/11 hijackers. we get more now from cbs's catherine herridge, including an exclusive interview with two former investigators.>> reps that's my dad.en his father >> reporter: eagleson is now leading a group of 9/11 families battling their own government to release still-secret f.b.i. files from the case. >> it's a ten-year-long investigation, that specifically investigated the role that the kingdom of saudi arabia played in supporting the hijackers. >> reporter: the case, code-named operation encore, centered on the two hijackers that lived in san diego, and who assisted them. is that the first mosque they went to in san diego? >> this is it right here. >> reporter: danny gonzalez was an f.b.i. agent who worked on operation encore, and showed us the neighborhood the hijackers lived in. this is his first television interview about the case. >> 19 hijackers cannot commit 3,000 mass murders by