Shocking new developments have come to the fore about the night when a white supremacist threw the bodies of a teen couple down a mine shaft after slicing their throats.

On Wednesday, 35-year-old Morgan Henderson testified against her former boyfriend Jerrod Baum after he was charged with aggravated murder, according to a Daily Mail report.

In December 2017, 41-year-old Baum reportedly murdered 18-year-old Riley Powell and his 17-year-old girlfriend Brelynne 'Breezy' Otteson (pictured above) as his girlfriend watched in horror. The duo's bodies were discovered several months later in March 2018.

According to Henderson, Baum became angry when he saw the teenagers sharing marijuana with his girlfriend at their Mammoth, Utah, residence. On the night of December 30, Baum allegedly told Henderson: "I told you, you couldn't have guy friends."

Moments later, when Henderson thought the couple had left, Baum had surprisingly calmed down and pulled a fleece jacket and thin black gloves from her closet. "His anger completely turned off, and he was charming," Henderson remembered.

But to her horror, she saw the two teens tied up in the back of Riley's Jeep after Baum led her outside. According to Fox 13 Now, Henderson said, "Jerrod told me to get in the car, and I felt I was scared. And, I listened to him. I knew that something bad was happening. It wasn't a normal situation."

Henderson and the couple were then driven to an abandoned mine shaft near Eureka known as Tintic Standard No. 2. Addressing the Probo 4th District Court, Henderson said, "I thought I was going to die."

Baum subsequently led the group through snow and sagebrush when Ottenson told him she was pregnant and allergic to sagebrush, Henderson recalled. When the teenager asked to be untied as her hands were going numb, Baum responded by saying, "No. We're almost there."

Eventually, Baum stopped the vehicle in front of the 1,800-foot open mine shaft. "I realized even if we listened, it wasn't going to end well," Henderson told the court.

The deranged boyfriend then forced Henderson and Otteson to their knees in an "execution style" position and instructed Powell to stand in front of them. According to the Salt Lake Tribune, Henderson "felt like we were an audience" at the time.

When Otteson broke down in tears, Powell asked Baum if he could kiss her one last time. However, he refused. Baum would then begin brutally stabbing Powell, who shouted, "I'm dying!" Henderson said.

When the teen fell to the ground, Baum waved at him and said "Goodbye Riley, you piece of s**t." An autopsy report later revealed that Powell had been stabbed several times and his throat had been cut wide open.

 

Ottenson continued to cry and pleaded with Baum that she would keep mum and not tell anyone about what had transpired. In response, Baum held Otteson in his arms and told her "it's okay darling" before Henderson felt something warm on her leg. 

Henderson later realized he had slit the young girl's throat and it was her blood that she had felt on her leg. "There was so much blood," she added.  

Baum then proceeded to dump both Powell and Otteson down the open mine, where they fell 100 feet down the shaft onto a ledge. "Like lambs to the slaughter, they didn't even fight," Henderson said Baum told her.  

He then began covering up evidence with dirt and warned Henderson to stop crying. "He looked manic. He looked high. He looked overjoyed," she continued.

"He said the next time I start crying about stupid Riley, I need to think about my little boy and whether I want him to grow up."

 

Baum then bleached and burned the young couple's clothes, hid the knife he used in an oil barrel and placed Powell's keys in piles of dirt before hiding his jeep.

The night before the couple disappeared, Powell had agreed to come to Henderson's home in a Facebook conversation later uncovered by authorities, who then brought in both Baum and Henderson for questioning. During the interview, Henderson claimed to be oblivious of what had happened to the pair.

But as the months went on and Powell and Otteson's families continued to search for them, she became consumed with guilt.

However, she decided to get high on magic mushrooms and kill herself in the mountains fearing Baum would hurt her son if she cracked. "I had tremendous guilt, I felt responsible," Henderson said. 

On her way to the mountains, authorities stopped her vehicle for speeding and found a rifle, an ax, and multiple knives in her car. It was then that Henderson decided to finally confess to her boyfriend's crimes. "I wanted those families to have closure," she said. "I wanted them to know what happened."

 

Baum was arrested just hours after Henderson led authorities to the couple's bodies. The killer was subsequently charged with aggravated kidnapping, desecration of a dead human body, witness tampering, aggravated murder, and obstruction of justice.

As part of her plea agreement, Henderson was charged with felony obstruction of justice after she agreed to testify against Baum in court. She is set to be released from prison once Baum's case is closed.

In retaliation, Baum's defense team fought hard against Henderson's testimony, bringing up her schizoaffective disorder, bipolar disorder, and depression, and even questioning whether she could tell the difference between reality and fiction.

They also brought up her shock therapy for depression and her consumption of psychoactive mushrooms in a bid to discredit her memory.

According to the autopsies, the teen's hands were both bound behind their backs. However, according to Henderson's claims, Otteson and Powell's hands were tied in the front. A judge will determine following the testimony if there is substantial evidence against Baum to stand trial. He could face the death penalty if convicted for his alleged crimes.

The trial continues.