ROCKLIN, Calif. – Two California teenagers were arrested after they gave one of the girl's parents milkshakes spiked with prescription sleeping pills so she could use the Internet past her curfew, police said.

The medicated shakes worked, but the parents became suspicious when they woke up groggy the next morning, Rocklin police Lt. Lon Milka told The Sacramento Bee in a story Thursday. They obtained a drug kit from police so they could test themselves for tampering,

The tests came back positive, and the couple went back to police with the results. Their 15-year-old daughter and her 16-year-old friend were taken to Juvenile Hall on Saturday and booked on suspicion of conspiracy and willfully mingling a pharmaceutical with food, Milka said.