Police officials are desperately searching for the author of a handwritten note that was slipped under the doors at the University of Alaska Anchorage police department.

Police officials said that the unusual, anonymous note tipped them about a savagely beaten 18-year-old teenager who was left to die in a deserted downtown Anchorage house scheduled for demolition Wednesday.

"The note left there stated that a male had been assaulted and was left inside residence to die," Anchorage Police spokeswoman Jennifer Castro said. "The person indicated they couldn't live with their self knowing this information and wanted to pass it to authorities."

The note said the writer felt obliged to tell someone.

"They said they couldn't live with themselves, that they had to tell, they had to say something," Shell said.

When officials from the university and the city reached the location of the house, they found James Clinton in the basement, unconscious and in critical condition, Monday night. They also found an identity card in his pocket

"It's my understanding he was beaten around the head and the face, the whole body," police spokeswoman Anita Shell said.

 The victim was immediately taken to an Anchorage hospital where he remains in critical condition.

"We have not yet spoken to the young man because of his medical state," Shell said.

Police said that Clinton was not a university student. According to whas11.com, the doors of the house were locked; it was surrounded by a fence and occasionally patrolled by a private security firm.

However, they did not reveal how the perpetrators got in and out of the house.

"How they were able to enter there is perplexing to me," Shell said.

Officials need to investigate the attack and gather information about it.

"One of those is time frame - trying to determine how long he was in this house for," Castro said. "In terms of the assault, was there one big incident? Were there multiple assaults that were occurring over periods of time?"

The home, located a block away from the main Anchorage federal building, which includes the federal courthouse, was demolished Thursday. It was owned by Covenant House, which runs a shelter for homeless teens across the street. The property will be used for parking.