CENTERVILLE — A plastic milk container and genealogy.

Centerville police used both of those items recently to figure out who allegedly attacked a 71-year-old woman while she was practicing the organ in a church meetinghouse. It's the same technology used by authorities to identify and arrest the Golden State Killer last year.

On Nov. 17, a Saturday night, a woman was alone in a chapel of The Church of Jesus Christ of Latter-day Saints at 270 N. 300 East in Centerville. The doors to the building were locked.

"Someone began pounding on the door to the chapel, where she was playing. She ignored it because she was alone. She said that it went on for some time before the pounding stopped," according to a newly unsealed search warrant filed in 2nd District Court.

Soon after the pounding on the door stopped, the woman was grabbed from behind while still sitting at the organ and was attacked.

"Her attacker put her in a rear chokehold and pulled her straight back off the bench," the warrant states. "The attacker strangled her to the point that she lost consciousness. She reported that she believed she had lost consciousness multiple times."

As detectives began investigating the case, they found a rock was thrown through a window and the suspect stood on a garbage can to get through the window, according to the warrant.

"During the initial investigations, blood was found on the windowsill and on the doorknob to open the door and exit that room," the warrant states.

The blood was sent to the Utah State Crime Lab to be analyzed, but it did not match with anyone in the FBI's national DNA database.

That's when the detective working the case tried a different approach.

"I began looking into using genealogy and DNA as a means to pointing us in the right direction to locate the suspect," he wrote in the warrant.

DNA was first sent to Parabon Labs in Virginia. Information generated from that company "was then uploaded to GEDmatch and was investigated by a team of genealogists lead by Cece Moore and work for Parabon Labs. GEDmatch is an open data personal genomics database and genealogy website," the warrant states.

It's the same technique that led to the arrest in 2018 of Joseph James DeAngelo, 72, the alleged Golden State Killer, who is accused of killing more than a dozen people and committing more than 50 rapes throughout California in the 1970s and '80s.

On March 27, Centerville police met with genealogists from Parabon Labs.

"They created an extensive and detailed report that did not say who the suspect was but pointed us in a direction which required a continued investigation," the warrant states.

The group was able to identify a relative of the teen, who they suspected may be a great uncle, according to the warrant. Detectives did research on the uncle and learned he "has a nephew that lives a couple blocks south of where the crime occurred," the warrant states. And the nephew has a 17-year-old son that lives with him, according to the warrant.

On April 11, Centerville police had the school resource officer at the boy's high school watch the teen as he ate lunch.

"(He) had a juice box and a small plastic milk container. When he threw those items into the garbage, I had (the officer) move the garbage can into a closet, without drawing attention to himself," according to the warrant.

Detectives responded to the school and got the items out of the trash can. The items were tested at the Utah State Crime Lab and a match was found between DNA collected at the church and DNA taken off the milk container, according to the warrant.

The boy was arrested and taken to juvenile detention.