The FBI was also present at the property, with agents seen entering and exiting the home throughout the day.
The investigation is connected to 44-year-old Eugene Horsch, who is facing federal charges.
According to investigators, the federal charges allege Horsch, a convicted felon, was in possession of firearms and fake DEA and FBI credentials.
Aerial footage from last week showed investigators working at the property, with many wearing protective suits. At one point, a person was seen carrying what appeared to be testing tubes from the property.
The investigation traces back to June 19, when officials said a park ranger noticed a black BMW parked in a prohibited area near Independence Mall.
According to court documents, Horsch and a woman were inside the vehicle, and the woman had identification belonging to a missing person.
Police said a search of the home uncovered an extensive amount of chemicals, drugs, guns and nearly 120 pieces of ballistic evidence.
Documents obtained by Action News show investigators also found zip ties, a handwritten note mentioning serial killer Ted Bundy and references to ways to dispose of trash.
“Every other day there’s been a car out front that’s it – making sure the scene wasn’t being tampered with or going into the house,” said one resident.
Investigators also found a 55-gallon drum connected to water lines.
Many questions remain as the investigation continues. Horsch is scheduled to appear in court in August.