EUREKA Utah (News4Utah) –  Nikka Powell felt betrayed and now angry after learning who may be responsible for her brother’s murder.

Friday,  the state Medical Examiner confirmed the bodies found in a mineshaft near Eureka were those of Riley Powell and Brelynne “Breezy” Otteson.

Jerrod Baum, 41, is under arrest suspected of murdering the two teens.  Authorities cracked the case after Baum’s girlfriend Morgan Henderson allegedly told them where the bodies were and that Baum stabbed them to death.

The motive is unclear.  In a probable cause statement, Henderson told authorities that Baum was angry that Powell and Otteson were at their home without his presence.

At a news conference Thursday, family members said “jealousy” caused their deaths.  But no one elaborated.

Friday, News4Utah met with Nikka Powell and the mother who raised both of them Linda Powell.  Powell is their biological grandmother, but she raised the children and considers herself their mother.

According to Riley’s sister, her brother and Henderson were once were dating.Henderson is 34 years old and Riley would have turned 19 years old next month.

She said Henderson was actually dating Riley’s best friend before he died in a car crash.  After that, she said Riley and Morgan began seeing each other.

“My brother and her started having a thing you know and after Jerrod got out of prison, she got with Jerrod and wow,” Nikka Powell said.

Riley’s sister recalled Baum and Henderson running into her in Eureka.  She said it was after Riley and Breezy went missing.

“(Henderson) says I’m sorry about your brother and I hope you guys find him and gives me a hug,” Powell said.

In a probable cause statement filed by detectives, it claimed Henderson knew all along that she knew what Baum allegedly did.  She told authorities that Baum stabbed them to death and dumped the bodies into the mine shaft near Eureka.

But it took several interviews with Henderson before she divulged what she knew.

Nikka Powell said during that same encounter with Henderson, Jerrod Baum came over to her as well.

“When Jerrod came over to pick her up he told me the same thing you know, ‘I hope you find your brother,’” said Powell.  “He acted like nothing you know. I don’t know how anyone can do that.”

Linda Powell who raised the children said Baum’s arrest also vindicates her side of the family.  Linda and Bill Powell are divorced.  Bill Powell has been a spokesman for Riley from the outset.

Documents from a search warrant conducted at Linda Powell’s home and witnesses targeted members of her household.

“They owe me an apology,” Linda Powell said.  “They’ve ruined us all the way around.”

She said one of the witnesses who fingered her family to police, owns the property where she rents and wants them gone.

Meanwhile, both Linda and Nikka Powell said Baum should face the death penalty if he’s charged and convicted of the murder.  They also say Henderson is equally to blame and should be charged with murder as well.

“Every time I see a picture of them I’m like shaking,” Nikka Powell said.  “It’s insane. I don’t understand it.”