CAMBRIDGE (CBS) – One of Massachusetts’ most wanted bank robbers is now behind bars. Cambridge Police are thanking an alert bystander and his smart phone for making that happen.

Robert McWilliams’ photo and description were posted on the “Mass Most Wanted” website for other alleged bank robberies, but it was an attempted bank robbery in Kendall Square on July 26th that got him.

Cambridge Police Commissioner Robert Haas says an alert bystander snapped a picture of the suspect outside the Eastern Bank, after recognizing he’s the same man who robbed the bank on July 7th.

That bystander is Ed Grigoryants who works for the Cambridge Innovation Center near the bank.

WBZ NewsRadio 1030′s Bernice Corpuz reports

“I took a quick snap with my I-phone and ran back into the bank,” he says. “I asked ‘You recognize this guy?’ and they said ‘Actually yes. We do!’”

Cambridge officers arrived in minutes and pounced on 38 year-old Robert McWilliams with their guns drawn.

Grigoryants was given a $300 check for his tip.