Bonaparte, Iowa ? A 22-year-old man has been charged with murdering his parents and three teenage sisters at their home in southeastern Iowa, authorities said Sunday.

Shawn Bentler is accused of gunning down five family members and faces five counts of first-degree murder, the Van Buren County Sheriff’s Office in Iowa said. He is being held on a $2.5 million bond at the Adams County jail in Quincy, Ill.

The victims were found early Saturday near Bonaparte, according to the sheriff’s office. They were identified as Michael Bentler, 53; his wife, Sandra, 47; and their daughters Sheena, 17; Shelby, 15; and Shayne, 14. Autopsies were planned Sunday.

The sheriff’s office said it received a 911 call from Shayne Bentler at 3:38 a.m. Saturday and that she told the dispatcher her brother was “going to do something.”

According to sheriff’s documents regarding the 911 tape, a gunshot is heard in the background and someone screams, “Shawn, no!” The line then goes dead.

Authorities said they received a second 911 call at the same time from the cell phone of Sandra Bentler. That call went unanswered.

Bentler was arrested Saturday in Quincy, Ill., about 60 miles from the family’s home, on an unrelated charge of possession of drug paraphernalia, according to the Adams County sheriff’s office.

Bentler could be extradited to Iowa as soon as today, said Jim Saunders, of the Iowa Department of Public Safety.

Investigators have not offered a motive for the killings, Saunders said. “It’s going to take them awhile,” he said.

The sisters attended Harmony High School. School officials said they will have counselors available today to speak with grieving students.