Dzhokhar Tsarnaev found guilty on all 30 counts. But there were bomb sniffing dogs at the start and finish. The Tsarnaevs planted their bombs after the finish (for the top finishers).
How did Tsarnaevs know to avoid the start and finish times? How did they know the time after the finish would be clear?
Did someone tip them off to the time to drop the backpacks, if they did? Or the time the bombs would go off?
Were they just lucky?
If the dogs didn’t sniff, you must find who tipped.
According to some comments, the back pack color mystery was never resolved at trial. The back packs the Tsarnaevs wore to not match the black color of the back pack exploded according to indictment. There is still a mismatch between the tattered remains shown in court according to some.
This is a critical inconsistency. Whose backpacks were the bomb backpacks?
This is draft and preliminary. The above is hypotheses and speculation. Comments and corrections welcome. Please restate as questions. All other disclaimers apply.