INDIANAPOLIS – An inmate tried to make it look like his cellmate had killed himself.

But video showed D’Angelo Smith wrapped a bedsheet around his cellmate’s neck and pulled until he stopped breathing, according to court documents.

The investigation into the death of Charles Barron Jr. began Sunday night, when the 36-year-old was found dead in his cell under suspicious circumstances at the Criminal Justice Center.

According to court documents, video from inside the cell showed what happened. The surveillance video showed Smith putting white socks over his hands like gloves and then wrapping a bed sheet around his hands.

He checked multiple times to see if anyone is watching as Barron lay on his cot, according to court documents, and then jumped on Barron’s back.

“Barron is seen waking up and struggling” with Smith while being strangled, according to court documents. As Barron struggled against him, Smith continued to apply pressure until Smith stopped moving. He checked Barron’s pulse to make sure he was dead, investigators said.

Smith wiped down surfaces inside the cell. He then took off Barron’s pants and dunked his cellmate’s clothing into the toilet to wet it. Investigators then said Smith tried to stage the scene so it looked like Barron had used a blanket and his pants to hang himself.

The deputy who initially found Barron believed he’d hanged himself, according to court documents, and flagged down a nurse so they could perform CPR. After they pulled Barron out of the cell and tried to save him, Smith took off down the hall.

Deputies gave chase and took him back into custody. Smith was then placed in a holding cell and later moved to a different location once investigators realized Barron hadn’t killed himself.

During an interview with investigators, Smith said he “had to do something” because he believed Barron noticed he was “trying to send a message through the camera to the guard.” Smith admitted he strangled Barron and kept the pressure on until he stopped breathing.

“Just did it for extra-long,” Smith told detectives, adding that he’d held on for an “extra two minutes” to make sure Barron was dead. After it happened, he said he “frantically” cleaned up the scene and made it look like a suicide so “that deputies would not kill him.”

Police arrested Smith on a murder charge.

Smith was in jail in connection with an arson case on June 18. Police arrested him on preliminary charges of arson and criminal mischief after firefighters reported seeing him light a dumpster on fire, according to court records.