Clark County District Attorney David Roger said William John Keck will face a criminal charge for allegedly killing the 18-week-old fetus of his wife, Angelique, during an attack this week at a Las Vegas apartment complex, the Las Vegas Review-Journal said Thursday.

Keck had already been charged with fatally shooting 26-year-old Jonathan Lestelle on Monday and attempting to kill his wife, who was carrying Lestelle's unborn child.

The filing of a criminal charge in relation to the fetus' death comes after authorities initially said the fetus was not at the required age for a homicide charge to be applicable.

Current Nevada law mandates that a fetus must have reached 25 weeks gestation to be applicable for a homicide charge.

Roger told the Review-Journal that the new homicide charge against Keck was based on a different state law that could carry a 10-year prison sentence if a conviction is earned.

"We did some research of the definition of an unborn quick child," he said. "It is any movement of a fetus in a mother's womb."