>> mr. gard, you know, under court precedence under the law police officers alone can walk up to front door, knock on the door and talk to the resident in order to uncover evidence of a crime. it's no different with a dog. >> woodruff: what about the other case? this was the dog on the handle of the door of the car the dog smelled something. >> right, and there the question is was that probable cause for the search. and probable cause has to be more than a suspicion and the courts when they try to determine whether there was probable cause because a criminal defendant is challenging the search looks at all the circumstances. here the florida supreme court looked at the reliability of the dog, aldo, and wanted the government and law enforcement to pro produce evidence that this dog was reliable. how was it traind? was the handler traind? was it certified? and mr. gar for the state of florida said that these were extraordinary requirements and he was supported by the obama administration's lawyer