On October 22, 2013, in United States v. Katzin, the U.S. Court of Appeals for the Third Circuit held that police and federal agents must obtain a warrant prior to attaching a GPS device on a vehicle. In doing so, the Third Circuit became the first federal appeals court to add a warrant requirement to the practice of GPS tracking by the police. The court also held that the good faith exception did not excuse the warrantless use of a GPS device, and that law enforcement’s reliance on out-of-circuit or distinguishable authority alone was insufficient to support a finding of good faith. This Comment argues that the Third Circuit took a mistakenly narrow view of the good faith exception, and failed to further the purpose of the exception as determined by the U.S. Supreme Court. This Comment contends that on rehearing en banc, the Third Circuit conducted a superior good faith analysis of the law enforcement conduct in Katzin, and correctly reversed the district court’s decision to apply the exclusionary rule.