Matthew Sepi, left, shot two people, one fatally, after he was confronted in a Las Vegas alley in 2005. Seth Strasburg, right, is serving a prison term of 22 to 36 years for shooting and killing Thomas Tiffany Varney on Dec. 31, 2005.Credit...Left, Jae C. Hong/Associated Press; Right, Nicole Bengiveno/The New York Times Late one night in the summer of 2005, Matthew Sepi, a 20-year-old Iraq combat