http://www.globalanimal.org/2013/04/19/will-dogs-nose-for-crime-find-second-boston-bomber/95856/
There were dogs used in the search and you are probably correct that 9000 people messes up the track. I was told that initially the dogs traced the suspect to basement of house. The suspect was hiding there but had left. The dogs could not find the suspect after this location.
Anyone the location of the house where he was in the basement???
I would like to see how far away it was from the boat.