Jurors listened Wednesday as a man called two teenagers who broke into his central Minnesota home "vermin" on an audio recording shortly after fatally shooting them.

Byron Smith also could be heard saying he was doing his "civic duty" on the recording, which was played during his trial. He is charged with first-degree premeditated murder in the deaths of Haile Kifer, 18, and Nick Brady, 17, in Little Falls.

Smith, 65, argues that he feared for his life that Thanksgiving Day in 2012 and shot the teens in self-defense.

Smith was alone when the teens broke in and didn't alert anyone about the shootings until the next day.

Authorities who searched Smith's home testified Wednesday that they found an audio recorder that was turned on, an operating surveillance system, and a cellphone-jamming device. - AP