The cause of death for three sisters who were tragically found dead at a campsite has been revealed by the authorities.

Paityn Decker, 9, Evelyn Decker, 8, and Olivia Decker, 5, were last seen during a scheduled visit with their father, and just days later, all three were found dead, per PEOPLE.

The discovery was made on Monday, June 2, and now a manhunt is intensifying for their father, 32-year-old Travis Decker, who is wanted in connection with the triple homicide.

The Wenatchee Police Department confirmed that the three girls were found dead after investigators located Decker’s white 2017 GMC Sierra pickup truck near Rock Island Campground in Chelan County.

Decker, however, was not at the scene.

The situation escalated dramatically with authorities now charging Decker with three counts of first-degree murder and one count of kidnapping. He was previously facing custodial interference charges.

“It is unknown whether Decker is currently armed, but he may pose a significant risk, if approached,” police said, also confirming that he has prior military experience.

The grisly details surrounding the discovery paint a picture of calculated movements and a chilling scene.