CLAYTON, Mo. – Trenton Forster was convicted of first-degree murder for killing St. Louis County police officer Blake Snyder in October 2016. Forster is challenging that verdict, seeking post-conviction relief.

“A post-conviction relief is generally collaterally attacking a conviction and trying to establish that something was constitutionally infirm with the conviction, such as ineffective assistance of counsel or jurisdictional issues,” said attorney Scott Rosenblum, Rosenblum, Schwartz & Fry.

Trenton did not appear in court Thursday morning. Judge Kristine Kerr said he will not testify.

The defense claims Foster is bipolar, and made a snap decision when he saw Officer Snyder in the dark outside the house where he was staying that October morning. They are making a case for diminished capacity defense.

“Diminished capacity is not what we would typically call ‘not guilty by reason of insanity,’” Rosenblum said. “[It] is a defense where an expert would typically say because this individual is suffering from some sort of organic mental disease, that that would keep this individual from forming the necessary intent to commit the crime.”

Colleagues, friends, and family of the fallen officer were in court, reliving a painful situation.

Officer Snyder’s widow, Elizabeth Tucker, told FOX 2 in a statement, “I have no doubt that our justice system and the rulings regarding Blake’s murderer will continue to be upheld. As much as this process pains myself and Blake’s family, we understand the judicial process and the right to appeal. However, we have faith that our prosecution team did their due diligence and that the choices and verdict regarding the trial were made correctly and justly.”

The court is set for a case management conference on June 2 at 10:30 a.m.