Edlib, yeah, i starting to think in same way as you, but actually even don't know what to think.
Anyway, Russian media now are just filled with such of conspiracy theories, making parallels mostly to 9/11 (that was used for invasion to Iraq and Afghanistan). People really afraid that the USA now wants to start a campaign in Caucasus that should disturb there's weak stability that was established there in last decade. Literally people says that "US has very serious troubles with their economy, so they looking for a way to resolve it starting a new war where fighting sides should have only losses, while the USA get a gain".
Some of idiots even says that those two Chechens committed those crime as revenge for US support to Syrian terrorists. Another people says: The United States got harsh but necessary lesson. In middle of 90s they directly called Chechen terrorists as "Freedom Fighters", supporting widely them in their war against Russia. They took shelter to many of those terrorists, treated them as heroes, so now they pay for "carrying snake in pocket".
Anyway, Russian society remains very anti-american for all of those troubles that the USA made to Russia in recent decades, so i really don't know what to think.