Wagoner County officials made an arrest on Friday in the December death of a woman.
Joshua Addington, 22, faces first-degree murder charges of his 30-year-old girlfriend Brooke Nicole Kinas.
Investigators say he tried to convince them she committed suicide by hanging herself with the seatbelt in her car.
But they say his story and the evidence just didn't add up.
"The initial report said that it was a suicide and that she was strangled by a seat belt in the car," Wagoner County investigator Danny Elliott said.
Investigators say Addington was arrested for obstruction of justice and booked into the Wagoner County jail for lying to them during the investigation.
"He was telling us that he walked the victim inside the house after the party was over and at some point in the evening she must have gotten up and went to the car and hung herself," Elliott said.
Information from the medical examiner's office and evidence from the scene didn't back up Addington's claims.
"We did some tests, some scenarios, using the same vehicle and we found it in our testing impossible to do it in the position he said he found her in," said Elliott.
The investigation reportedly shows a history of domestic violence between Addington and Kinas had increased while Kinas tried to end her relationship with Addington.
Kinas had a six year old daughter.