COLORADO SPRINGS | Jurors found a Colorado Springs man guilty of two murder charges on Tuesday and began hearing testimony on whether the former Fort Carson soldier should be sentenced to death or life in prison for killing his former girlfriend and an acquaintance.

Glen Galloway was found guilty of first-degree murder in the death of Janice Nam and second-degree murder in the death of Marcus Anderson. The first-degree murder conviction makes Galloway eligible for the death penalty under Colorado law.

The sentencing phase, which got underway Tuesday, could last for weeks, The Gazette of Colorado Springs reported .

Prosecutors decided in February to seek the death penalty against Galloway for the May 2016 fatal shootings, the first time El Paso County has sought a death sentence in a decade. They argued that Galloway killed Anderson then drove Anderson’s truck to Nam’s house, where he broke in and killed her.

Prosecutors said Galloway killed Nam in retaliation for her testimony that he stalked her and violated a restraining order she filed against him. He was convicted in October 2015, but he failed to appear for sentencing in January 2016.

In two applications for restraining orders in 2014, Nam wrote that she feared Galloway wouldn’t stop coming after her until he killed her.

Galloway’s attorneys said he killed Anderson in self-defense and shot Nam during a mental break following Anderson’s death.

They were prevented from arguing self-defense during closing arguments by District Judge Gregory Werner, who ruled that Galloway’s attorneys had presented no evidence of it during the trial. Galloway did not testify during the trial after Werner ruled that Galloway could be cross-examined by prosecutors about the deaths of both Anderson and Nam if he took the stand.