Was Motorcycle in Times Square Stampede Modified to Sound Like Gunfire?

Was the Times Square stampede caused by a biker with a tricked-out motorcycle? That's what cops want to know after pandemonium broke out at in the area Tuesday as hundreds ran for their lives after hearing what they feared were gunshots. Cops say the panic was a false alarm. The exhaust on a motorcycle can be modified to make it louder, sounding like rapid gunfire. The NYPD confirmed to Inside Edition that they are looking into whether the exhaust on the motorcycle that triggered the panic.