CA10: Govt used Doppler radar to determine if defendant was in house, but court doesn’t have to decide constitutional question

Defendant was wanted for not reporting to probation, and there was a warrant for his arrest. The government used Doppler radar to determine whether defendant was in his house at the time. The court has concerns about the use of radar to scan for people in a house, but doesn’t reach the question because of the independent source rule. United States v. Denson, 2014 U.S. App. LEXIS 24616 (10th Cir. December 30, 2014):

Separately and as we alluded to earlier, the government brought with it a Doppler radar device capable of detecting from outside the home the presence of “human breathing and movement within.” All this packed into a hand-held unit “about 10 inches by 4 inches wide, 10 inches long.” The government admits that it used the radar before entering — and that the device registered someone’s presence inside. It’s obvious to us and everyone else in this case that the government’s warrantless use of such a powerful tool to search inside homes poses grave Fourth Amendment questions. New technologies bring with them not only new opportunities for law enforcement to catch criminals but also new risks for abuse and new ways to invade constitutional rights. See, e.g., Kyllo v. United States, 533 U.S. 27, 33-35 (2001) (holding that using warrantless thermal imaging to show activity inside a home violated the Fourth Amendment). Unlawful searches can give rise not only to civil claims but may require the suppression of evidence in criminal proceedings. We have little doubt that the radar device deployed here will soon generate many questions for this court and others along both of these axes. At the same time, in a criminal proceeding like ours the government is free to rely on facts gleaned independently from any Fourth Amendment violation. See Murray v. United States, 487 U.S. 533, 537 (1988). And in our case Mr. Denson acknowledges that all of the facts we’ve outlined above were discovered independently of the potentially problematic radar search–a fact that requires us to defer those questions to another day.