The Butler County District Attorney’s Office wants a visiting judge to recuse himself from the upcoming trial in the death of a 15-year-old boy who was struck while he was riding his bike in October 2023. Additionally, the public defender’s office wants the judge to recuse the district attorney’s office, according to recent court filings.

The motions were filed in advance of a trial scheduled to begin Sept. 21 for Joshua A. Rivera, 41, who is facing third-degree murder, homicide by vehicle and other charges in the death of Aiden Lutz.

Butler Township police charged Rivera with striking Lutz on Dutchtown Road and fleeing the scene while driving with a suspended license Oct. 19, 2023. He is being held in the Butler County Prison in lieu of $500,000 bail.

Assistant district attorney Ben Simon filed a motion Friday, Aug. 7 asking Senior Judge Christopher St. John to recuse himself as the trial judge. According to the motion St. John made biased statements during a meeting held in chambers following an Aug. 4 hearing, despite not having all the evidence.

During the meeting with Simon and public defenders Joseph Smith and Kimberly Hudak, who are representing Rivera, St. John made unsolicited statements that he did not view the case as a third-degree murder case when he agreed to preside over it and he did not believe the prosecution can prove its case for third-degree murder, according to the motion.

St. John made personal comments that children are irresponsible, children riding e-bikes on the road don’t think about what they are doing and Lutz probably turned in front of Rivera causing him to strike Lutz, according to the motion.

The judge told the district attorney’s office to convey his views to Lutz’s family in trying to reach a plea agreement, according to the motion.

Simon’s motion argues that St. John does not have all the prosecution’s discovery information. It also notes that “even a jury is advised they are not to formulate any opinions on the case until all the evidence and testimony has been presented at trial.”

St. John also said in the meeting that he had been a public defender for decades, according to the motion.

Simon argues in his motion his office has concerns that St. John led the defense attorneys to believe they would succeed in a motion to acquit Rivera of the third-degree murder charge.

St. John scheduled a hearing on the motion for Monday.

In a motion filed Monday, Smith and Hudak asked St. John to reconsider his June 27, 2024, order denying their motion to recuse the district attorney’s office.

That motion was filed April 11, 2024. It asked for the recusal due to a conflict of interest arising from political actions and campaign materials mailed to all Republican voters in the 2023 election for the district attorney’s office and ongoing civil litigation in which the district attorney is a party based on similarly situated claims.

The motion refers to a suit filed against District Attorney Richard Goldinger and several others alleging libel, slander and defamation by attorney Jennifer Gilliland Vanasdale stemming from the 2023 election in which she ran against Goldinger. St. John dismissed the case in October 2025. However, Gilliland Vanasdale appealed the decision to Superior Court, which has not issued a ruling.

Smith and Hudak’s motion mentions the defense motions argued during the Aug. 4 hearing. Those motions seek dismissal of the case against Rivera because the prosecution exceeded the time limit to bring the case to trial. The motions also requested the exclusion of potential evidence uncovered while a previous ruling was under appeal in Superior Court. St. John has not ruled on either of those motions. As of the Aug. 10 filing, Rivera had been incarcerated for 1,024 days, according to the motion.

The motion asks St. John to recuse the district attorney’s office and to allow the attorney general’s office to take over the prosecution. A hearing on the motion was not scheduled as of Friday.