Idaho authorities say they're working around the clock to find those responsible for a "heinous" triple murder at a rural home in the Boise foothills. One man has been arrested on theft counts.

"When I say this crime is heinous, that is probably an understatement," Ada County Sheriff Gary Raney told reporters Wednesday. "Somebody who violently, without cause, without any provocation that I know of, killed three innocent people. We are working 24 hours a day with everything we've got to put that person in jail."

A 22-year-old Nampa man arrested Wednesday is accused of grand theft and forgery but not murder, the sheriff's office said in a statement.

Adam M. Dees was arrested at a Boise electronics store. He is accused of three felony counts each of grand theft and forgery and a misdemeanor count of carrying a concealed weapon without a permit.

Deputies also seized a 2003 black Subaru Legacy with a gold panel that Dees was driving.

Two men and a woman were found dead Tuesday at the home. The victims' names were not immediately released.

Raney declined to speculate on a motive or say if anything was missing from the home. He said the victims were related, and the killings occurred sometime between Sunday evening and Tuesday morning.

He said police wanted to hear from anyone who saw the Subaru near the murder scene between Sunday and Tuesday night.

"I want the community to help us put the right person in jail," the sheriff said.

"It's hard for me to fathom even after 31 years of law enforcement what could possibly motivate somebody to do to these people what they did," he said.

The killings took place in what records say is a three-bedroom, three-bathroom home on about 20 acres with a total value of about $800,000. Authorities say the property has horses and other buildings.

He said police responded after a family member called Tuesday.

"I've probably not seen a bloodier or more violent murder occur," Raney said.

He said other law enforcement agencies were investigating, including the U.S. Marshals Service.