BREAKING: Criminal investigation launched after Matthew Mayich’s devastating collapse

Matthew Mayich, a 21-year-old St. Louis Blues prospect and Arizona State defenseman, has been hospitalized in critical condition since collapsing during a preseason training session on August 20. But the situation has now escalated well beyond a university matter, with campus police opening a formal investigation into what happened that morning.

The Arizona State University Police Department is actively looking into whether any criminal conduct took place in connection with Mayich's collapse, according to two individuals with knowledge of the probe who spoke to The Athletic on condition of anonymity. One of those sources confirmed that officers have already begun contacting players for interviews.

The police investigation is separate from the internal "review" Arizona State has said it is conducting. ASU athletic director Graham Rossini previously drew a distinction between the two, telling Arizona Sports 98.7 that the school's process is about "reviewing the facts and understanding the scenario" rather than suggesting wrongdoing occurred. A university spokesman called the police involvement "standard practice" when serious injuries happen on campus.

Rob Carey, a former deputy chief attorney general of Arizona now representing the Mayich family, called the police probe "a step in the right direction." However, he urged investigators to preserve all evidence, including material that may have been deleted, use subpoenas and warrants, and interview witnesses separately while protecting them from retaliation.

Critically, Carey also provided a devastating update on Mayich's condition. He stated that describing the young player as being in a coma is no longer accurate. "A coma indicates deep unconsciousness and recovery is possible," Carey said. "His body ceased functioning in a fundamental way, and this condition is irreversible."

The training session in question reportedly took place at Sun Angel Stadium and was led by Tim Ziesel, a 39-year-old with military experience who is not employed by Arizona State. The Athletic confirmed Ziesel's involvement, noting he has not responded to repeated attempts at contact. His attorney, Buddy Rake, has characterized the session as more of a team-building exercise, a claim Carey dismissed as "fictional."

Players who spoke with Carey described a roughly 50 to 60 minute session involving sprints, planks, pushups, and bear crawls in 86-degree heat with 51 percent humidity and no wind. Water intake was reportedly restricted based on effort levels. The National Weather Service recommends 15 minutes of rest for every hour of activity under those conditions.

Tempe Fire Medical Rescue responded to a call for a heat-related illness at 8:31 a.m. that day. Within ten minutes, first responders radioed a nearby hospital to prepare for a patient with a "serious heat emergency."

Mayich transferred to Arizona State from Clarkson University this past offseason. The Blues selected him in the sixth round of the 2023 NHL Draft, 170th overall.

The police investigation remains in its early stages, and the questions surrounding accountability, player safety protocols, and the university's response are only intensifying.