A grand jury will decide whether to indict John Snow after a preliminary hearing Monday before Boone County District Judge Michael Collins.

Boone County Sheriff's Detective Bruce McVay testified Monday that Snow threatened Patricia Volpenhein of Covington two weeks before she was found dead in a field in Boone County.

"John put a gun to her head and asked if it scared her, (and) she said, yes, it did scare her," McVay said.

Sanitation workers found the body of the single mother wrapped in two plastic tarps Sept. 12 at a construction site near Ky. 8 and Amsterdam Road.

Deputies are still looking for the small-caliber gun they say was used to shoot Volpenhein twice in the head and the weapon used to stab her several times in the neck. McVay said investigators have surveillance tapes showing Snow purchasing two tarps at a Covington auto parts store.

Snow was convicted of manslaughter for shooting to death his pregnant, 15-year-old girlfriend, Wendy Castleman-King, in 1993 and was paroled in May.

In the Volpenhein case, Snow pleaded not guilty last week to charges of murder, tampering with evidence and being a persistent felony offender. Snow is in Boone County Jail, held without bond.

Volpenhein left her Russell Street home with Snow in his pickup truck Sept. 11 at 3 p.m., McVay said.

Police say Snow later asked his uncle if he could discard a truck bed liner at his Walton farm, but was turned down. Police later found the liner in a Dumpster on Main Street in Covington.

Workers who found Volpenhein's body told police they saw Snow driving past the site when they were waiting for police to arrive, police testified Monday.