"They were as far left and right as you can be. We had heard of no friction whatsoever other than they just were difference of political opinion."

"Both of them walked their little dogs at about a mile and a half circle, a nice little dog trot. I'd see them out walking, maybe they might stop and speak with each other."

Says a neighbor of Rand Paul's, quoted in "Attack leaves Sen. Rand Paul with 5 cracked ribs" (CBS News).

Police are saying nothing about the motive for the attack, but we do know that Paul was tackled from behind with "high velocity severe force." We can probably infer that the attacker — Rene Boucher — came onto Paul's property with an intent to attack him and surprised him and that it was not some kind of argument that arose and escalated in a face-to-face encounter.

Another thing we know is "Boucher is an anesthesiologist and a pain specialist." I'd want to look into whether Boucher had a drug problem.