BUCKHANNON, W.Va. -- Three men were in jail Wednesday after police said they fatally stabbed and shot an Upshur County man during a planned attack in January.State Police began investigating the disappearance of Joshua Richard Oberg, 29, when he did not return to his Buckhannon home on Jan. 23. Witnesses said he was last seen in a vehicle with Jesse Lee Heater, 28, of Buckhannon, and Robert Eugene Siron, 30, of Weston, according to a criminal complaint filed in Upshur County Magistrate Court.A confidential informant told police this week that Heater admitted that he and Siron attacked and killed Oberg and then hid his body along Bull Run Road in Upshur County, according to the complaint. Police investigated the area Tuesday and discovered Oberg's skeletal remains in a shallow grave. Troopers, FBI agents and Buckhannon police determined Rodolfo Villagomez Correa, 32, of Buckhannon, allegedly paid cash for Heater to kill Oberg. Heater then shared the money with Siron for assisting in the attack, according to the criminal complaint.The men were charged with first-degree murder and are being held without bail. Heater and Villagomez are in Tygart Valley Regional Jail and Siron is in North Central Regional Jail.