A Casper woman who allegedly told investigators that she killed her boyfriend "because his life was so bad" pleaded not guilty this morning (Tuesday morning) to a charge of first-degree murder. Dawn M. Rock could be sentenced to life in prison if she's convicted. The Casper Star-Tribune reported on its Web site that Natrona County District Attorney Michael Blonigen said in court this morning that he will not pursue the death penalty.

According to court documents, the 34-year-old Rock told police she shot 36-year-old Kenneth Walkinshaw at their home in March after he complained about how bad his life was.

Police say the couple had argued earlier, and that Rock said Walkinshaw had tried to choke her.