. >> ifill: don borrelli, you were on the new york city joint terrorism task force and we now know that there are maybe 2,000 tips or more coming into the boston police department and the f.b.i. is helpful? is it a lot to get through? >> it's both. we've seen in context of the medical teams talking about the word triage, where they had to triage the wounded individuals. this is the theory going on now with the f.b.i. they're getting thousands of leads from citizens from informants, from our partners overseas, from everywhere and they've got to prioritize those leads and triage them and work the most positive ones first and the ones that are potentially perishable. >> ifill: we have been watching, juan zuarte, investigators literally combing the streets on their hands and knees, picking up every little thing. if it rains tonight as the reporter with burr is saying, does that impede the investigation? >> it will a bit. the crime scene is outside. the wind and the rain and the elements no doubt will have an impact so the f.b.i. investigators, the federal and state authorities will r no dou