The presumption is that TWA 800 may have been shot down by a stinger missile, although according to other accounts the Chinese have modified the Stinger to give it a longer range, and one of those modified Chinese missiles might have been used. This remains speculative because of the FBI cover-up. It's also possible that the plane was downed by an American missile during fleet exercises.
Naw. TW 800 may have been brought down by a shoe-bomber though. There were trace amounts of C4 residue reported early in the TW 800 investigation. The residue was "explained away" by the FBI, who attributed it to an on-board test of search dogs looking for explosives. THAT was ridiculous.
Considering what Reid tried to do, we need to re-look at what really happened to TW 800