An Iowa man was arrested for first-degree murder for allegedly killing a woman in April 2021 then placing her head on a stick in a park. 

Nathan James Gilmore, 23, was taken into custody on Friday in relation to the death of 29-year-old Angela Nicole Bradbury. 

Detectives alleged that he referenced the murder in a social media message and drew a "satanic goat’s head in the shape of a pentagram" with numbers that alluded to the brutal slaying, according to a criminal complaint. 

Gilmore told police that he picked a woman up who matched Bradbury's description from Cerro Gordon County Jail on April 6, 2021. He initially said that he dropped her off at a home in Mason City, but later allegedly changed stories and said he dropped her off five blocks from the jail.

A teenager found the skull at Greenbelt River Trail Park on July 12, 2021, roughly three months after the murder took place. 

Bradbury was reported missing in February of this year by her family, who said they hadn't heard from her since April 2021. The Iowa State Medical Examiner's Office was able to identify the skull as belonging to Bradbury using DNA and dental records provided by her family about a week after she was reported missing. 

Additional human remains belonging to Bradbury were discovered at the trail in April 2022. A medical examiner determined that her manner of death was a homicide. 

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After Gilmore said he left Bradbury on April 6, 2021, he told police that he went to work then returned home that evening. Detectives allege in the complaint that GPS coordinates place him in the park. 

"GPS records obtained from Gilmore’s Facebook account showed that on the evening of April 6, 2021, Gilmore’s Facebook account was active in an area northwest of Greenbelt River Trail Park at approximately 7:21 p.m. and active in an area southeast of the Greenbelt River Trail Park at approximately 8:37 pm," the complaint said. 

Gilmore later allegedly threatened in a message to a friend of his ex-girlfriend that the man would "be lookin like the body they found outside Mitchell." 

Detectives searched Gilmore's home on Friday and found a drawing that "depicted a satanic goat’s head in the shape of a pentagram with what appeared to be blood spatters drawn on it."

Numbers that were written on the drawing allegedly referenced Bradbury's death. Detectives believe that "04-06" coincided with April 6, the day Bradbury was murdered. The numbers, "43.3, -92.8," are allegedly abbreviated GPS coordinates of the park. 

Gilmore is being held on a $1,000,000 bond at the Mitchell County Jail. It wasn't immediately clear if he had an attorney who could speak on his behalf.