Mark Karasek, 22, who pleaded not guilty to second-degree murder after his father, Zdenek Karasek, was shot and killed on Jan. 9, will have his competency hearing Oct. 21, according to the King County Prosecuting Attorney’s Office.

As previously reported, the two had allegedly been arguing all day prior to the incident at their home in unincorporated King County near Redmond. According to the report, several individuals in the Karaseks’ home witnessed the two arguing and heard gunshots, though no one actually saw what had allegedly happened.Mark was charged with second-degree murder.