CitizenApathy

I'm not sure if this is an appropriate question or not, but here goes:

I've read that before the bomb went off that there was an abnormally high amount of police at the marathon, and that they had dogs sniffing for something which is a possible indicator of a received threat or perceived abnormality. Can you confirm or deny? Did you notice anything different about this marathon that may have been different from others?

Thank you in advance for a response, for helping those people, and I am glad that you are safe.