A medical examiner confirmed Friday that the two bodies found in an abandoned mine shaft, just inside the southwest Utah County border, belong to a teenage couple missing since late December.

The bodies of 17-year-old Brelynne “Breezy” Otteson and 18-year-old Riley Powell were recovered by police Wednesday with knife wounds and their hands bound behind their backs, according to a probable cause statement for the arrest of 41-year-old Jerrod William Baum, of Mammoth, a town near Eureka in Juab County.

The medical examiner’s report noted stab wounds and blunt force trauma, said Utah County Sheriff’s Sgt. Spencer Cannon. He noted that the blunt force trauma could have come from falling 100 feet down the mine shaft, rather than from a physical assault.

The report also said Riley and Breezy ”sustained multiple injuries that would have been fatal,“ according to Cannon. It also contained a more detailed description of the stab wounds, Cannon said, but the county is not yet releasing that information.

Baum has been held in the Utah County jail without bail since Wednesday on suspicion of two counts of aggravated murder, two counts of aggravated kidnapping and two counts of abuse or desecration of a human body. Formal charges have not been filed.

(Courtesy Utah County jail) Jerrod William Baum

Breezy and Riley had been dating about four months and lived together in Eureka before their disappearance. They reportedly went to the home Baum shared with his father and his girlfriend, Morgan Henderson, late at night on Dec. 29 to smoke marijuana with the woman, the statement said.

Baum had forbidden Henderson, 34, from having male friends and found out that the teens had come over, Henderson told police. He told her “it was too bad because he has never killed an innocent before,” according to the statement.

After Henderson thought the teens had left, she told police, Baum said he knew they’d been there and brought her outside, where she saw the two teens tied up in the back of Riley’s Jeep.

Baum allegedly drove Riley’s Jeep, with Henderson and the teens inside, to the area of the abandoned Tintic Standard No. 2 mine, which has a shaft 1,800 feet deep.

At the pit, the woman told police, Baum used a knife to kill Riley and Breezy before dumping the bodies into the shaft. On Wednesday, Police recovered the bodies from a ledge about 100 feet down.

Baum reportedly “made Riley suffer” but “felt bad” about killing Breezy and “made it quick and painless” for her, Henderson told police. Since the slayings, Baum had become “somewhat emotional about Brelynne,” the statement says.

(Courtesy Amanda Hunt) Riley Powell
(Courtesy Amanda Hunt) Breezy Otteson

After dumping the bodies, Baum and Henderson went back to their home, the girlfriend told police. At the house, Baum allegedly threatened Henderson with strangulation.

Henderson then drove Riley’s Jeep to Cherry Creek Reservoir — where the vehicle was later found by police — while she followed Baum, who was driving a truck, she told police. The truck got stuck, Henderson said, and they used a tie-down strap to pull it out.

Baum reportedly hid the teenagers’ cellphones in a stocking, which he threw into a sludge barrel near their home. Henderson later led police to the mine and the barrel, where officers found the stocking, destroyed phones, rope, used duct tape, pieces of two knife sheaths, roofing nails, parts of a cigarette carton, baby wipes and plastic sacks.

Police also found a camouflage tie-down strap that matched the one found attached to Riley’s Jeep.

Police appear to have interviewed Henderson at least four times over the course of the investigation, with Henderson progressively revealing more details about what happened.

(Photo courtesy of Sanpete County Sheriff's Office) Morgan Henderson

At the first interview Jan. 9 — a week after the teens’ families reported them missing — police interviewed Baum and Henderson together at their home, and both denied knowing anything about the disappearance.

As the investigation continued, police found a Facebook message thread between Henderson and Riley on Dec. 29, in which Riley agreed to meet at Henderson’s house. All social media activity on Riley and Breezy’s accounts stopped about 11 p.m. that night.

The second time police interviewed Henderson, Jan. 25, they spoke in a deputy’s vehicle while Baum watched her from outside. On this occasion, Henderson acknowledged that the teens had stopped by her home for about 40 minutes on the night of Dec. 29, smoked marijuana and left. She denied knowing where they went or what happened to them after their departure.

Henderson later said she hadn’t been truthful to detectives before “for fear that she would get into trouble [with Baum and Baum’s father] for having people over,” the statement said.

Then on Sunday, Henderson was pulled over for speeding and booked into the Sanpete County jail on suspicion of drug- and traffic-related offenses, as well as being a restricted person possessing a firearm. Police interviewed her again, and she told officers that Baum had told her about killing the teens.

On Monday, Henderson took police to the barrel and to the mine shaft where she “believed” Baum dumped the bodies after the killings.

During a Tuesday interview with police, Henderson said that she’d actually been present when Baum killed the teens.

At a Thursday news conference, Breezy’s aunt Amanda Hunt and Riley’s father, Bill Powell, questioned why the teens had to die.

Bill Powell, left, and Amanda Hunt, right, listen to questions during the press conference at the Utah County Sheriff's office on Thursday, March 29, 2018, in Spanish Fork, Utah. The press conference came after Jerrod William Baum was arrested in relation to the deaths of Riley Powell and Brelynne "Breezy" Otteson. (Evan Cobb/The Daily Herald via AP)

“What was he thinking?” Bill Powell, said of Baum. “What was his problem? What went wrong? Why did he have so much hate?”

Early in the investigation, police focused on Riley’s mother, Mistie Carlson, and her boyfriend, Lee Shepherd, who live in the small Tooele County town of Lofgreen with Riley’s grandmother, Linda Powell, and her boyfriend.

When asked Thursday about the investigation’s apparent shift from Carlson and Shepherd, Cannon kept quiet.

“There are some things we know that we can’t release yet,” Cannon said.

In January, Baum had been on supervised parole in a federal firearm case, and on probation in a drug and firearm case with state officials.

He was a person of interest in the homicide case as of Jan. 30, when he was arrested on suspicion of probation violations and booked into the Juab County jail, a news release from the Juab County sheriff’s office says.

State court records show that probation officers searched Baum’s home on Jan. 31, in connection with the two missing teens.

The agents found a handgun case and subsequently learned from Baum’s girlfriend that it had held a .45-caliber handgun, which, she told authorities, Baum had handled and showed her how to load, court records say.

On Feb. 13, Baum was charged with second-degree felony possession of a firearm by a restricted person in connection with the .45 in 4th District Court in Juab County.

On Wednesday, he was transferred from the Juab County jail to the Utah County jail in light of the new allegations in the homicide case.

Utah County jail records also show Baum is suspected of tampering with a witness, obstructing justice and possession of a dangerous weapon by a restricted person in the homicide case, and he has a federal detainer from the U.S. Marshals, based on an arrest warrant.

Cannon said Friday that no other arrests had been made in connection with the teens’ case. Henderson is being held at the Sanpete County jail on unrelated charges, as previously stated.