A man accused of killing his in-laws with a package bomb that exploded in their rural Tennessee home has pleaded not guilty.

Richard Parker is charged with two counts of felony first-degree murder, two counts of premeditated first-degree murder and unlawful possession of a prohibited weapon. Through a public defender, Parker pleaded not guilty to all charges at an arraignment hearing Tuesday.

Authorities say the package bomb exploded in his in-laws home in Lebanon, which is about 30 east miles east of Nashville. The blast killed 74-year-old Jon Setzer, a retired lawyer. Setzer's 72-year-old wife, Marion, died later at a Nashville hospital.

The 49-year-old son-in-law told a judge that he didn't have the money to make his $1 million bail.