A father and son held two U.S. Forest Service biologists at gunpoint inside a trailer near Gumboot Lake Campground in Shasta-Trinity National Forest for approximately 15 hours before surrendering to federal authorities early Friday, July 17. Both victims were released unharmed.

Joseph Charles Henrichsen, 49, approached the two biologists, both women, on the morning of July 16 carrying an AR-15-style firearm while they conducted routine fieldwork near the campground in Siskiyou County, FBI investigator Russell Quiniola stated in an affidavit filed in the U.S. District Court for the Eastern District of California.

Henrichsen then zip-tied both women’s hands behind their backs, and along with his adult son, Phoenix Jose Phillup Henrichsen, 23, confined them inside the trailer at gunpoint.

The elder Henrichsen used one of the victims’ phones to call and describe holding two “fed” employees “hostage from the Forest Service,” according to the U.S. Attorney’s Office for the Eastern District of California.

That call activated a multi-agency response involving the Siskiyou County Sheriff’s Office, state law enforcement, and the Federal Bureau of Investigation (FBI) Hostage Rescue Team deployed from the agency’s headquarters in Quantico, Virginia

Law enforcement deployed drones to locate the trailer in rugged terrain west of Interstate 5, near the Oregon border.

Both suspects surrendered at approximately 2:30 a.m. Friday following more than nine hours of negotiations. Siskiyou County Sheriff Jeremiah LaRue confirmed the release at a press conference that morning.

“I want to say how profoundly grateful and relieved we are that our two employees were released safely,” U.S. Forest Service Chief Tom Schultz said. “Their well-being continues to be our highest priority.”

Joseph and Phoenix Henrichsen appeared Monday in federal court before U.S. Magistrate Judge Allison Claire in Sacramento, each charged with kidnapping a federal employee and aiding and abetting. The motive remains under investigation.