CLEVELAND COUNTY, Oklahoma - Jurors saw the worst of the evidence on Tuesday during Alton Nolen's murder trial.

Photos and physical evidence were revealed in court from the gruesome beheading incident in 2014 at Vaughan Foods.

Five law officers from the first responding officer to detectives with the Moore Police Department testified. They say the day started as a disturbance call. Many soon responded to what they thought was an active shooter setting. It eventually escalated to an officer involved shooting response.

One paramedic recalled the scene and his responsive conversation with Nolen in the back of the ambulance. He said Nolen was attentive and calm and able to answer all his questions.

Detective Jeff Griffin testified. He pulled out the knife that Nolen used during the attack. It was covered in blood. He also showed evidence of a bloody cloth found near Colleen Hufford's body.

Photos showed Hufford's body separated from her head. Both wide and close-ups were shown to the jury, some who seemed shocked by what they saw. Griffin describes Hufford's head as about 15 inches away from her body after the decapitation.

Nolen seemed un-phased by the evidence. Like he's been doing the whole trial, his eyes are closed and his hands are covering his ears.

Another detective, Jon Oliver, testified that he searched Nolen's vehicle at Vaughan Foods and then searched his apartment. Oliver found a Quran and written scripture, along with a 3-pack knife set that was missing two knives. Several items were taken as evidence.

District Attorney Greg Mashburn said on Wednesday, he will show other items found in Nolen's apartment. The medical examiner will testify. He will also show Nolen's interview from the hospital. Mashburn believes he can prove Nolen is guilty and mentally competent. The state plans to wrap up their case on Wednesday.

The defense is asking the jury to find Nolen not guilty by reason of insanity. Their case will likely begin Monday.