Emily Baucum, News On 6

TULSA, Oklahoma -- Funeral services will be held Saturday for two young Tulsa murder victims.

Freshman ORU student Carissa Horton and her boyfriend Ethan Nichols were shot and killed, execution style, Sunday night at Tulsa's Hicks Park.

It's a horrifying crime their families say they will never understand.

The Nichols and Horton families were bound together long before the senseless tragedy. Carissa and Ethan were childhood friends in Iowa. Now their families say -- they'll be together forever.

Like a lot of 18 year olds, Carissa Horton left home for college. But her parents back in Iowa knew she had a "home base" in Tulsa with her boyfriend Ethan Nichols and his family.

"It was just a comfort that they were here also," said Rod Horton, Carissa's Father.

Ethan's family says his relationship with Carissa had brought him closer to God.

"He had just really evolved into a man. That's the hard part," said Teresa Nichols, Ethan's Mother.

Carissa's parents say their daughter was beautiful, talented, and brilliant.

"She knew she was supposed to do something with her music," said Susan Gardner, Carissa's Mother.

Carissa was born with the gift of song. It was the last gift she ever gave her family.

"And she sang me a happy birthday song [over the phone] that afternoon," Rod said.

"That was the last time we talked to her," Susan said.

"That was the last time we got to hear her voice," Rod said.

A joyful phone call led up to the one that's every parent's worst nightmare, when Tulsa Police called to say Carissa and Ethan were found dead.

"I could not cry at the moment. My mouth was incredibly dry. I just remember being very disoriented and just in disbelief. It just didn't seem possible," Susan said.

Carissa's family drove all night from Iowa.

"We had to. We had to get to our daughter," she said.

Their 12-hour journey ended in even more heartbreak when they learned just how brutal the murders were.

"That was crushing. That people could be that cruel and that heartless. It doesn't make any sense," she said.

Both families fall back on their faith to move forward. Ethan's mother chooses to forgive the killers.

"We have free will. God gave us that. My son and Carissa chose the heaven side. These two boys have chosen the hell side," said, Ethan's mother, Teresa Nichols. "Hell is where they'll face their consequences."

Carissa's parents say their daughter's song was cut short on Earth, but she's still singing in heaven.

"You betcha. She's going to direct that choir," Susan said.

The memorial service is Saturday at 11 a.m. at Destiny Church in Broken Arrow.