Three sisters and their parents are dead in southeastern Iowa, and authorities say the couple’s son is a suspect.

Van Buren County officials say the victims were found shot at about four a.m. Saturday morning near the town of Bonaparte. It was not immediately clear what prompted the slayings.

Twenty-two-year-old Shawn Bentler was arrested today in Quincy,Illinois, on an unrelated drug charge. Authorities would not say if he has been charged with the deaths.

Fifty-three-year-old Michael Bentler and his wife, 47-year-old Sandra Bentler were found dead with their daughters, 17-year-old Sheena, 15-year-old Shelby, and 14-year-old Shayne.

The slayings have shocked residents of the tiny town, located on the state’s southeast border just north of Missouri.

The girls attended Harmony High School, where school officials were organizing counselors to speak with students when classes resume on Monday.

Radio Iowa