UNC School of Government blog post by Jeff Welty that explains the U.S. Supreme Court’s 2013 holding in Florida v. Harris. Harris holds that when a trained and certified drug dog alerts on a vehicle, that normally provides probable cause to search the car, even if there are no records regarding the dog’s performance in the field. However, challenges to drug dog reliability will likely continue because the case holds that defendants are entitled to make such challenges through cross-examining the testifying officer or by introducing his own fact or expert witnesses and that courts will determine the weight given to evidence regarding the adequacy of the dog and handler’s training, the team’s prior performance in the field, and other factors.