BILLINGS, Mont. -

A 23-year-old Billings man who pleaded no contest to stabbing two sisters to death in January 2012 is being sentenced Tuesday.

The Billings Gazette reports the state will argue that Andrew Scott Denning should be sentenced to 100 years in prison for two counts of deliberate homicide in the deaths of Rose and Daisy Edwards.

During his plea hearing, Denning said he didn't know why he stabbed the women. Police say it was because they refused to pay Denning for prescription drugs.

An autopsy found Rose Edwards likely died from a stab wound to her neck. She also had been choked. Daisy Edwards had numerous stab wounds, including one to her heart.

Denning has been jailed with bail set at $1 million since his Jan. 30, 2012 arrest.