COEUR D’ALENE, Idaho – Jonathan Renfro appeared in front of a judge Monday for the first day of the aggravation phase of his murder trial.

Renfro was found guilty Friday of first-degree murder in the death of Coeur d’Alene Police Sergeant Greg Moore. He was also found guilty of removing a firearm from a police officer, concealing a firearm, and robbery. Renfro killed Sergeant Moore in May of 2015.

The state called on nine witnesses Monday and most were Kootenai County deputies.

During opening statements the defense argued that any threats Renfro made while in jail were a result of him being provoked and “treated like an animal.”

The court heard testimony from Deputy Steve Malcom. Malcom told the jury Renfro said he had intentions to kill another inmate due to constant disrespect and harassment. Deputy Malcom also told the jury Renfro demonstrated how he could turn a towel into a baseball bat.

Another deputy testified about the same demonstration and told the jury Renfro said making the towel wet would make it harder and could “crack our skulls in.” The defense asked each deputy if Renfro ever harmed an inmate or detention officer while in jail and each deputy answered no.

The state brought up a conversation Renfro had with inmate Denver Hart about Sgt.Greg Moore's family.

According to Hart, Renfro said, "That's what you get when you marry a cop." The judge decided he will not allow Hart to talk about that statement regarding Sgt. Moore's family if he is called to testify.

The prosecution is seeking the death penalty in the aggravation phase of the trial. In this phase, prosecutors are trying to show that Renfro has the potential to commit another murder.

For the death penalty sentence to be on the table prosecutors will have to prove that Renfro murdered Sgt. Moore because he was an officer, there was intent to burglarize or rob Sgt. Moore, or that Renfro is a continued threat to society.

The state plans to continue its case Tuesday and the jury could begin deliberations by the end of the day.