Authorities were questioning a man arrested in Illinois after his parents and three teenage sisters were found shot to death at their home in southeastern Iowa.

Shawn Bentler, 22, 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, Ill., sheriff's office.

The Iowa Department of Public Safety said Bentler is considered a suspect in the slayings, but did not disclose a motive.

The victims were found early Saturday near Bonaparte, according to the Van Buren County 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 for Sunday.

At St. Boniface Catholic Church in Farmington, where the Bentler family worshipped, some parishioners wiped away tears Sunday as they knelt to pray, while others sat transfixed, their hands on their faces or clasped in prayer.

"You saw this in the Amish country when those girls were shot, and now it's in our backyard," youth minister Mike Linnenbrink said. "It's not surprising at all that we turn to church at this time. This is a tight community, not just in Van Buren County but in all of southeast Iowa."

The teens — a freshman, sophomore and senior — attended Harmony High School. School officials said they will have counselors available Monday to speak with grieving students.