Florida teen bludgeoned parents to death, then threw a house party, police say (VIDEO)

A 17-year-old South Florida boy was arrested Monday after allegedly bludgeoning his parents to death with a hammer, then hosting a house party for his friends that night with the dead bodies locked in a bedroom.

Tyler Hadley, of Port St. Lucie, Florida, "brutally and mercilessly" beat his parents to death on Saturday, probably sometime not too long after he posted a party invitation on Facebook at around 1:30 p.m., CBS News reported, citing local police officials. Hadley allegedly bludgeoned his parents on the head and torso with a 22-inch framing hammer, outside their bedroom, then dragged their bodies into the bedroom according to CNN. He covered the bodies with household items, including towels, books and files and apparently locked the door to the room.

Sometime after 9 p.m., between 40 and 60 people came to the house for the party, which lasted until early Sunday morning, according to the police. Some people at the party may have gotten wind of the killings but apparently nobody reported a crime and it was unclear whether any of the guests saw the dead bodies, according to CNN:

Port St. Lucie Police spokesman Tom Nichols said, "during the party and after the party, there was a rumor that perhaps Tyler had killed his parents."

Police officers showed up at the home at around 2:30 a.m. in response to a noise complaint, but didn't notice anything unusual, according to ABC News.

After receiving an anonymous tip, the police returned to the house around 4:20 a.m. Sunday, where they found beer cans strewn around the yard and inside the home and a 'nervous and panicky" Hadley, who said his parents were out of town, according to the Daily Mail. The police searched the house and found the bodies of Hadley's mother Mary Jo, 47, and father Blake, 54, in the locked master bedroom, under the pile of household items, with the hammer lying between them.

Police believe the mother was killed before the father and then the bodies were dragged into the bedroom, CBS News reported. Port St. Lucie Police Capt. Don Kryak said the bodies were only partially covered by the household items, which had apparently been used in an attempt to hide them, according to ABC News.

According to CNN, quoting Kryak:

"The crime scene was certainly a merciless killing," the police captain said. "It was brutal."

Hadley was arrested on two counts of first-degree murder; he is being held without bail and will be charged as an adult, according CNN, which cited police officials.

The reason for the murder was unclear, but according to WSVN-TV:

Adam Gibbs attended the party. "They said he killed his parents with a hammer because they wouldn't let him throw a party," he said.

WOKV reported that one of the teenagers at the party said Hadley had killed his parents because they "wouldn't let him throw a party."

The father worked for Florida Power and Light and the mother was a local school teacher, WSVN said. An older son lives out of state.

According to Kryak, Tyler Hadley had dropped out of St. Lucie Centennial West High School, but then later, he took classes at Indian River State College, CNN reported. According to court documents, the Hadleys were being sued in St. Lucie County for $15,000 after Tyler Hadley hit and injured a child pedestrian while driving a car registered to his father in June 2010, the Daily Mail reported.