How do we know for sure that the crack pipe(s) was/were Chad's?
Chad has escaped the scrutiny of the media and not much is known about him, he has kept a low profile. All we know is that he is MG's step-son, CS's fiance' and now has custody of his 2 children. He has a job, he and CS live together and rumors are that he was not home on Monday night - he may work nights for all we know.
Even without any confirmation, I can guarantee that LE talked to him and know everything there is to know about him - he's the live-in bf of the mother of a missing child, he would be at the top of the list of suspects along with RC, MC, CS, Gannys, GreatGrannys, Grampas, Step-family members, Uncles, Aunts, GreatAunts, RSO's, SO's, friends, ex-lovers, neighbors, Martians and other alien life forms.