High school graduation and prom season have arrived, and along with the corsages, caps and gowns come the parties. It's a notion that can strike fear into the heart of any parent, and for good reason. These days a child's bad behavior doesn't just lead to disappointment but can actually lead to a jail cell -- for the parents.
Ask Paula and Barry Spencer, from Falmouth, Maine.
Watch the full story on "20/20: With Parents Like These" TONIGHT at 10 p.m. ET.
Last June, after their 18-year-old son Nicky's high school baseball team won the state championship, they agreed to host a celebration for the players. The Spencers set out the ground rules: no more than 50 guests, and absolutely no drinking or drugs.
As guests started arriving around 7 p.m., they were served barbecue along with lemonade, iced tea and water. In an interview with "20/20," the Spencers said they weren't naive to the fact that their teenage guests might try to sneak in something harder.
"I thought people were going to attempt to bring in beer and alcohol, but we were watching for it. I was actually right at the front of the house watching kids come in," Barry Spencer said.
As the sun set, the atmosphere at the party started to change. More kids were arriving, and Paula Spencer, who was stationed at a window looking out onto her backyard, had a harder time monitoring the scene.
At 10:30 p.m., an anonymous tip came in to the Falmouth Police Department that the Spencers were hosting an underage drinking party. Sgt. George Savidge responded to the call.
"I pulled up to the house and there were probably 30 cars in the roadway. Immediately a gentleman came out and identified himself as Mr. Spencer. He said he was hosting an alcohol- and chemical-free party. He asked that I help them monitor the area for kids that would sneak in with alcohol or drugs," Savidge said.
Savidge told Barry Spencer he would monitor the street, but that Spencer was responsible for his property. Savidge saw no evidence of underage drinking, so he left.
But by 11 p.m. the party had ballooned to around 100 rowdy teens, some of whom had snuck in alcohol and many of whom were now openly drinking. Rather than shut down the party, the Spencers attempted damage control, dumping whatever alcohol they could grab down the sink.
"I invited these kids to our home to celebrate, and I didn't have clear evidence that they were all drinking. I just felt like, is it fair to shut it all down because of a few kids spoiling it for everyone else?" Paula Spencer said.
At 11 p.m. another Falmouth police officer made a traffic stop and found a drunk underage passenger in the car. When the officer questioned her, she admitted that she had just come from the Spencers' party. Police decided to head back to the house.
"At this point everyone seemed to be in a much higher state of intoxication. Now it looked like there was a party going on," Savidge said.
Police reports from that night noted 20 to 30 alcohol containers scattered around the back patio, a large marijuana pipe sitting on a table, vomit on the ground and a teenager passed out on a neighbor's lawn.