A 33-year-old Sedalia man accused of murdering a patient at Columbia??s Truman Veterans Hospital on Friday pleaded not guilty Thursday afternoon.Rudy Perez, Jr., claimed he was incompetent at the time of the murder of 77-year-old Robert Hill because he did not receive his medication for schizophrenia.Boone County Prosecutor Dan Knight has decided to maintain the first-degree murder charge against Perez. Knight has not decided if he will seek the death penalty.Perez entered two pleas. Hepleaded not guilty to first degree murder and he pleaded not guilty by reason of mental disease or defect excluding responsibility. In other words, defense attorneys said Perez murdered his fellow patient at Columbia??s VA Hospital because he was not on his medication for a mental disease. Perez must prove he suffered from a mental disease at the time of the murder. He must also prove he did not appreciate the wrongfulness of his actions.??I??m going to consider all of the information in this case," Knight said. "I??m going to try and do what is fair and what is right under the law.??Defense attorneys did not point fingers at who was responsible for not providing Perez with the proper medication at the time of the murder. They did say someone dropped the ball in regards to the patient care of Perez.Perez's attorney David Tyson Smith said, ??Had he been properly medicated and supervised, this could have been avoided. He was getting psychiatric treatment at the hospital while he was there for some of these mental health issues.??Defense attorneys said Perez and his family are remorseful about the murder. Investigators are still checking on why Perez was not on his medication at the time of the murder.Court documents showed that the assault that led to the murder of Hill was the second altercation between Hill and Perez on the day of the murder.