BOISE, Idaho -

A Boise man accused of setting fire to a home where a 74-year-old woman was found murdered has formally been charged with first-degree arson and burglary.

Forty-two-year-old Steven Roberts III appeared in court Thursday for his role in the September 2012 fire.

Weeks before the blaze, detectives found the body of former teacher Phyllis Ward inside the same home. Authorities say there is no connection to the crimes and the murder investigation is ongoing.

Prosecutors also say they intend to make a case that Roberts is a persistent violator and deserves a tougher sentence if convicted. Roberts was previously convicted of burglary and aggravated assault in 2006.

He is being held in the Ada County Jail on a $1 million bond.