BOSTON (AP) — Moments after investigators went before television cameras to broadcast photos of the two men in ball caps wanted for the Boston Marathon bombing, queries from viewers started cascading in — 300,000 hits a minute that overwhelmed the FBI’s website.

It marked a key turning point in a search that, for all the intensity of its first 72 hours, had failed to locate the suspects. While it’s unclear how much the tips that resulted helped investigators zero in, experts say it instantly turned up already intense pressure on the two men to flee or almost certainly be recognized — increasing the chances they’d make mistakes that would lead to them being exposed.