AMITE — Prosecutors filed a formal notice Monday that they would seek the execution of a man accused of killing a Loranger woman and her young daughter during a violent assault that spanned two states last month.

Daniel Callihan, 36, pleaded not guilty Monday during his arraignment at the Tangipahoa Parish Courthouse. He faces two counts of first-degree murder, two counts of aggravated kidnapping of a child and one count of unauthorized entry of an inhabited dwelling.

Previously, prosecutors accused Callihan of killing Callie Brunett, 35, and Erin Brunett, 4. It wasn't immediately clear why a third homicide charge was added; the sheriff's office, which investigated the case, did not return a call seeking clarification.

Callihan also faces charges in federal court and in Mississippi state court.

Callihan is accused of killing Callie Brunett, 35, and kidnapping her two daughters on June 13. One day later, 4-year-old Erin Brunett's body was found in a wooded area outside Jackson, Mississippi. The FBI said that Callihan told an investigator he wanted to keep the other kidnapping victim as a "sex slave."

An alleged accomplice, Victoria Cox, 32, faces similar charges in both states.