LAKEWOOD, Colo. (KUSA) -- Whatever was happening at 1250 Kline Street went quietly unnoticed for years.
Neighbors say there was no indication of anything unusual until Lakewood police made a bizarre discovery.
Officers are investigating how suspected human remains and objects of occult worship ended up in a tool shed.
"That would be very frightening," said neighbor Scott Keller.
Keller and his wife Kelly knew the woman who lived next door, but saythey knew very little about her husband who lived there until 1998.
"I never talked with her about her husband," Kelly Keller said.
Lakewood Police spokesman Steve Davis says the woman's husband died after leaving the house.
"He is now deceased and has been for very many years," Davis said.
Davis says the man's widow continued living in the house for 15 years, until a few months ago.
In all those years, she apparently never stepped foot in the tool shed.
"[The shed] has been undisturbed for that many years," Davis said.
The shed remained undisturbed until a realtor listing the house hired a cleaning crew to get the property ready for sale.
Those workers got a shock.
"Some kind of occult altar or occult worship going on in the shed," Davis said.
Police found an altar complete with candles, animal bones, animal skulls, even a machete.
Some items, including a skull mask with a black hood, were still laying in the backyard on Monday evening.
"There was a partial skull," Davis said.
Lakewood police think that partial skull, and other bones, may be human.
Police are sending them to an out-of-state lab for testing to determine if they are human, and if they contain any DNA evidence.
In the event that any of the bones are positively identified as beinghuman, detectives say it may prove very difficult to determine when andwhere they were obtained.
Lakewood police do not consider the house a crime scene, because they don't have any evidence that a crime was committed there.
Davis says investigators believe all the items were brought-in from somewhere else.
Even if the bones do prove to be human, that doesn't necessarily mean a crime was committed.
Police say human bones are sold on the internet, and it's perfectly legal.
Neighbor Carlos Fraire says the police department's findings freaked him out.
Investigators learned the man who once lived in the house worshipped the occult.
"It's weird that it's this time of year, right around Halloween," said Fraire. "I was like whoa. That's too close to home."
Whether it's black magic, or something else, the Kellers call it creepy.
"We'll have to keep our eye out for spooks, that's for sure," Scott Keller said.
Detectives are asking anyone who may information that would assist themin their investigation to call the Lakewood Police Department at303-987-7111.