The Churchill County Sheriff's Office is investigating the homicide of a 51-year-old Fallon woman who was killed Monday night.

Deputies found Lisa A. Onyon of Fallon had been stabbed at least once in the chest and determined there was an altercation that took place at the home place after being called to the residence by the suspect, 49-year-old Michael O. Johnson.

At 9:19 p.m. the Churchill County Sheriff's Office received a request for an ambulance to a residence in the 1100 block of McLean Road in Fallon.

After deputies arrived on scene first and discovered a deceased female inside the residence, the CCSO received a search warrant from Justice of the Peace Pro-tem Bill Lawry.

CCSO Sheriff Rich Ingram said he did not know if Johnson knew Onyon was dead when he called for an ambulance.

"We do know she was unresponsive," Ingram said.

The sheriff said Johnson did make statements to officers, but added those comments cannot be released at this time because they are part of the ongoing investigation.

The condition of the home, Ingram said, showed there was a dispute.

"The inside of the home displayed that some sign of an altercation took place," Ingram said.

Johnson, a roommate of Onyon, was taken into custody at the scene a short time after deputies' arrival for open murder. His bail has been set at $1 million.

Deputy District Attorney Craig Mingay said the open murder charge means Johnson could be charged with anything from voluntary manslaughter to first-degree murder, and added the actual charge will be determined by the results of the investigation.

Mingay said Johnson will be arraigned within 72 hours, but he did not have an exact time as will be determined by the justice of the peace's availability.

Results of Onyon's autopsy are pending and the investigation is ongoing.