FAYETTEVILLE, Ark. (KNWA/KFTA) — An arrest has been made in connection with the murder and disappearance of 28-year-old Allison Maria Castro.

According to Fayetteville police, Kacey Jennings, 29, has been arrested and is facing charges of capital murder and abuse of a corpse.

“Very tragic and awful situation,” said Sgt. Tony Murphy with the Fayetteville Police Department.

Allison Castro, 28. Courtesy of the Fayetteville Police Department.

Police responded to a residence and located Jennings on September 19 as he was experiencing an apparent drug overdose. After getting him the medical treatment he needed, police found more.

“Officers discovered more information that led us to believe that the suspect in this case had possibly killed his ex-girlfriend,” he said.

Fayetteville police spoke with Castro’s family and learned that Jennings and Castro were previously in a relationship and lived together. Castro was entered as a missing person on September 19 after the family was unable to contact her and an investigation was launched.

One week later, on Tuesday, September 27th, police arrested Jennings. He’s facing preliminary charges of capital murder and abuse of a corpse.

“Some of the information that’s been located during the investigation led us to believe that the body of Castro was moved, or was disposed of, so that’s the basis of the abuse of a corpse charge,” explained Sgt. Murphy.

“If I would have stayed with him longer, that could have been me,” said Jennings’ ex-girlfriend, Marilyn Merino.

She said they started dating after meeting through work, and were on-again, off-again for about four years. She said it’s been about a year since they broke up for the last time. She said she was shocked to see his mug shot pop up on her Facebook feed, which is how she found out about his arrest.

“My heart dropped, my stomach dropped,” she said. “It was a horrible feeling.”

She said she didn’t expect this from him, but her family wasn’t as surprised.

“They would always sense something in him. He always seemed angry all the time,” she said. “Or like, he just had a face of not being welcoming and not friendly.”

She got emotional when sharing what she would say to Jennings if she could.

“How could you take a family’s daughter away?” She said through tears. “I’m just so hurt and disgusted by what you did. You can’t take that back and I hope you have to deal with the consequences for the rest of your life.”

As the investigation unfolded, “additional information” was discovered that led to an arrest warrant for Jennings. He was arrested on September 26 after his release from a local medical facility.

Fayetteville police are working with other law enforcement agencies to locate Castro’s body.

“Our hearts go out to the family and we’re going to do our due diligence, and investigate this as well as we can to find justice for Ms. Castro,” said Sgt. Murphy.

“I’m praying for you and I’m praying for your family,” said Merino to Castro’s family.

KNWA/FOX24 did reach out to Castro’s sister, but she said the family is too devastated to speak publicly right now.

If you have any additional information concerning the investigation, contact Fayetteville police at 479-587-3555.