>> there for generations to keep on killing. >> they say the obama administration is less than forthcoming about their son's death. >> no one told us anything. >> but you know about the case? what happened to my son is what we know. >> zapatas hired former u.s. assistant attorney martinez to find out. >> the family would like answers and closure. >> a gun at the crime scene purchased near houston on behalf of accused drug dealer barba. the other by a dallas trafficking wing that included buyer osorio. police arrested carnet espinoza for killing zapat and wounding his partner avilla as they drove along a dangerous mexican highway. >> we understand there is a written directive for agents not to get on the road because it's dangerous. >> i'm shows the atf in dallas had evidence to bust the osillo ring three months