GROVER, Wis. (WFRV) - Charges of Homicide by Negligent Operation of a Vehicle have been filed against a Marinette County man accused of using his cell phone 'immediately before' a crash that killed two women in early June. A release provided by the Marinette County Sheriff's Office states that 46-year-old Scott Mathis faces two homicide charges relating to the June 2 crash in the Town of Grover that killed 44-year-old Elysia Kust and 73-year-old Mary Kust. ‘He’s just gone’: Heartbroken family and frightened Oshkosh neighborhood mourn 19-year-old after homicide According to the criminal complaint issued by the Marinette County District Attorney's Office, witnesses described that an SUV, driven by Mathis, was heading south on CTH W when he allegedly failed to stop at a stop sign at the intersection of CTH B, hitting the car with Elysia and Mary who were eastbound on CTH B. Both Elysia and Mary Kust were later pronounced dead. Authorities noted that an examination of Mathis' cell phone showed phone activity 'immediately before' the crash. Court records show that Mathis has been charged with: Two counts of Homicide by Negligent Operation of a Vehicle Felony G Up to 10 years in prison, a fine of up to $25,000, or both Family with De Pere area ties identified as 6 dead following central Wisconsin house fire Mathis is scheduled to make his initial court appearance at 8:30 a.m. on July 22. The Marinette County Sheriff's Office investigated the incident with assistance from the Peshtigo Police Department, the Wisconsin State Patrol, the Town of Grover Fire Department, the Marinette County DA's Office, and the Marinette County Medical Examiner's Office. No additional information was provided. Local 5 will continue to follow and update this story when more details are released.