One person was killed and another critically wounded in an apparent shooting in a field just outside Forestville, triggering a massive search of the rural area that continued deep into the night Friday.

A woman jogging near River Road and Trenton-Healdsburg Road partially witnessed the killing, according to preliminary reports transmitted over the Sonoma County Sheriff’s Office radio network beginning around 6:40 p.m. No suspects were in custody by 10 p.m., according to law enforcement communications.

Sheriff’s representatives did not respond to repeated telephone calls seeking confirmation of details relayed by radio throughout the evening.

The search centered on a field located north of River Road and west of Trenton-Healdsburg Road. Aided at times by law enforcement helicopters overhead using spotlights and infrared to light the area and detect hot spots, Sonoma County sheriff’s deputies were combing an area dominated by vineyards and cut through by the tree-shrouded Mark West Creek watershed.

The first reports of the killing came from a jogger running in the area who heard screaming and gunshots, and saw at least one person fall to the ground, according to law enforcement communications.

She did not have a phone, but borrowed one from a motorist on River Road to call authorities.

The report prompted a search by ground and helicopter, with deputies converging on a cornfield in the area as night fell.

The sheriff’s helicopter was overhead and was first to spot two figures on the ground as deputies searched the area, eventually bringing the witness closer to help pinpoint the crime scene. The SWAT team was called out as well.

Deputies said an encampment was in the area.

Paramedics tended to the wounds of the survivor, who was airlifted to a local hospital. An update on the survivor’s condition was not available late Friday. The body remained where it was found, presumably so detectives could investigate once the area was safe to enter. Deputies set up a perimeter around the scene and were methodically inspecting the area at press time.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.