Authorities have “a suspect in mind” after four people were found dead and one injured at a marijuana farm in rural Oklahoma, but no arrests have been announced. The bodies were found after authorities responded to a reported hostage situation at the farm.

Capt. Stan Florence of the Oklahoma State Bureau of Investigation said authorities believe the suspect knew the victims, who were found dead Sunday night at the 10-acre farm west of Hennessey, about 55 miles northwest of Oklahoma City.

“They all know each other,” Florence said. “Don’t know if they’re related, or if they’re coworkers, but certainly these individuals were, we believe, all familiar with each other.”

Authorities have not identified the victims or said how they were killed. Police would only confirm that the victims were men and women, CBS affiliate KWTV reported.

The injured person was taken to an Oklahoma City hospital. The case is being investigated as a quadruple homicide.

The Kingfisher County Sheriff’s Office initially responded to a reported hostage situation at the farm but requested help from state authorities, Florence said.

“At this point, we have a suspect in mind,” Florence told reporters Monday at the property. “We have no information specific to be able to share … at this point.”

Investigators don’t believe the suspect is still on the property after an extensive ground and air search, KWTV reported.

Police searched the property late Sunday and Monday using drones, helicopters and on the ground, Florence said, but did not find the suspect.

“There’s a lot to unravel with this case,” he said. “It’ll take a little time for us to process it.”

Officials said the owners of the property are international, but the Oklahoma Medical Marijuana Authority did not share any information about the owner, KWTV reported.

Oklahoma voters legalized medical marijuana in 2018 and the industry quickly boomed, thanks to an open-ended law that put in place fewer restrictions than in other states.

In March, voters will decide whether to legalize the recreational use of the drug.