RUSSELLVILLE, ARK., JAN. 15 -- Two capital murder charges were filed today against Ronald Gene Simmons, accused of killing 14 family members and two other people last month.

Simmons, 47, who previously was charged in the slayings of two other people Dec. 28 in Russellville, was accused in the latest charges of killing his wife, their seven children and four grandchildren in the largest family mass murder in U.S. history.

Pope County prosecutor John Bynum said he filed two charges because the family slayings apparently occurred in two separate incidents.

Bynum said seven victims found in a shallow common grave near Simmons' home were killed Dec. 23 or Dec. 24 while seven found in the house or in car trunks died Dec. 26.

The bodies at Simmons' home near Dover were found after his arrest in connection with a 25-minute shooting spree Dec. 28 in Russellville. The shooting spree ended with Simmons surrendering peacefully to the police chief.

Simmons, who is undergoing psychiatric examination at a state hospital in Little Rock, earlier was charged with two counts of capital murder and four counts of attempted capital murder in the killings of Kathy Kendrick, 24, a secretary who acquaintances said had rejected Simmons' romantic advances, and J.D. Chattin, 33, and the wounding of four others at four downtown businesses.