The last known person to see Tina Sisk-Gavach alive was found guilty of second-degree murder in another state last month. Now, investigators in the nearly five-year-old Ardmore cold case are pushing for answers.

Ardmore police began focusing on 45-year-old Kalvin Allison as a person of interest in the alleged murder of Sisk-Gavach after he was arrested over 700 miles away in Pensacola, Florida, in May 2019. Allison reportedly withdrew money from his neighbor’s bank account just three days after his neighbor was murdered.

Florida investigators were able to connect Allison with the murder based on evidentiary items found at his residence and he was sentenced to life in prison in October for second-degree murder, grand theft and destroying evidence.

Allison had previously been a person of interest in the Ardmore cold case based on the fact that he was the last known person to see the victim alive, Ardmore Police Department Capt. Eric Hamblin said.

Sisk-Gavach was first reported missing in January 2015. After several months of an intensive effort to locate the 42 year old, investigators reportedly discovered her remains buried in a shallow, handmade grave on a property in Lone Grove.

The victim’s remains were mostly decomposed by the time they were found, making it difficult for medical examiners to determine a cause of death, Hamblin said. There were no signs of cuts in her rib cage, fractured bones or a bullet in the head.

Five years later, Sisk-Gavach’s cause of death is still marked as “unknown” in the medical examiner’s report.

“The problem is that in this case, the medical examiner’s report makes it very difficult to move forward. But having said that, we never close homicide cases,” Hamblin said. “If it’s an unsolved case, it’s open. We have investigators assigned to all of our cold cases and they’re continually following up on leads, continually looking for new ways to solve the crime.”

Hamblin said Allison is believed to have moved from Ardmore to the Pensacola area sometime around the discovery of the victim’s body in July 2015.

“I know that he moved there shortly after the discovery of her body or shortly before — we weren’t sure at the time which, but either right before or right after her body was discovered, he moved to Florida,” Hamblin said. “Strange, I know.”

The case may be hard to prosecute due to a lack of evidence, Hamblin said. However, investigators are currently working to see if they can elicit a confession from Allison. If enough evidence is obtained, Hamblin said charges will be sent over to the District Attorney’s office.

“The family deserves closure, we need to know what happened,” Hamblin said. “If it’s a crime and we’re able to prove that it’s a crime, the District Attorney will file a charge and (Allison) will have to answer for his crime.”