Spencer also fired shots at law enforcement officers and helicopters assisting law enforcement. No law enforcement officers were injured during the search for Spencer.
Everyone in the Iowa Hill area is urged to lock their doors and remain inside.
In an update on Sunday night, the sheriff's office said the search remained ongoing, noting the search is very challenging due to the area being very large, with dense forest and steep, rugged terrain.
But during the search, deputies located a murder victim they believe was killed by Spencer.
"As tactical teams worked to clear a home where Spencer had been earlier in the search, they located an adult female who had been shot and killed inside the home. At this point in the investigation, it’s believed Spencer murdered the woman before fleeing into the surrounding forest," deputies said.
The sheriff's office is being assisted by multiple other law enforcement agencies.
"Teams will continue searching throughout the night and will not slow down as we work to locate this armed and very dangerous individual," the sheriff's office said.
The sheriff's office described Spencer as a bald man with a goatee.