Ex-Milwaukee cop Michael Mattioli faces homicide charges. Here are the key figures in his trial

Former Milwaukee police officer Michael Mattioli is charged with one felony count of first-degree reckless homicide in the 2020 death of Joel Acevedo.

Acevedo died April 25, 2020, six days after after prosecutors allege Mattioli, who was off duty at the time, put the 25-year-old in a "rear naked chokehold" during an argument at Mattioli's house. Acevedo, Mattioli and two others had spent the previous evening partying together.

The trial begins Nov. 6, after a lengthy series of legal delays.

If he's convicted, Mattioli faces up to 40 years in prison and another 20 years on extended supervision.

Here's a closer look at some of the people who are expected to play key roles during the trial.

The victim: Joel Acevedo

Joel Acevedo was a security guard who aspired to a career in law enforcement. So, it was small wonder, according his family, he had friends who worked as police officers.

His family has described him as a "young man full of life whose laugh was contagious." He's said to have had a big heart and a penchant for cheering up friends and taking in stray animals until they could be safely returned to their owners.

Acevedo's parents, Maribel and Jose Acevedo, filed a federal lawsuit against Mattioli and Robert Roach, one of the first Milwaukee officers to respond that night.

Michael Mattioli, a former Milwaukee police officer, is accused of killing Acevedo while off duty

Mattioli was a 13-year veteran of the Milwaukee Police Department.

He resigned from the force in September 2020 after he was charged first-degree reckless homicide in Acevedo's death.

He was off duty at the time that prosecutors believe he applied the chokehold on Acevedo.

Mattioli, 36, has pleaded not guilty.

Mattioli defense attorney Michael F. Hart

A native of Flint, Michigan, Hart went to the University of Wisconsin-Madison and got his law degree from Michigan State University in 1988.

He practiced in the Detroit area before moving to Wisconsin, where he founded Kohler & Hart, LLP. The firm later became Hart Powell S.C.

Hart defended Sujata "Sue" Sachdeva, a former vice president for Koss Corp. who was accused of embezzling $34 million from the company. The case was one of the largest such embezzlement cases prosecuted in the Eastern District of Wisconsin. Federal prosecutors wanted Sachdeva to serve 15 to 20 years in prison. She got 11 years.

Hart represented April Novak, a Menomonee teacher accused in 2015 of having a sexual relationship with a 16-year-old student. She faced 12 counts of sexual assault of a student by school staff, and later pleaded guilty to three of them.

Mattioli defense attorney Craig S. Powell

Craig S. Powell received his law degree from UW-Madison in 2005. Hart and Powell are partners at the Milwaukee law firm Hart Powell S.C.

Powell leads the firm’s appellate and postconviction practice and has argued frequently before the Wisconsin Supreme Court and Court of Appeals.

His first appellate victory came in a case he began handling as a law student.

Prosecutor Paul L. Tiffin

Paul L. Tiffin is an assistant district attorney at the Milwaukee County district attorney's office.

Tiffin got his law degree from Marquette University in 1986.

Tiffin led the prosecution of Dan J. Popp, who a jury convicted in 2018 of killing three neighbors inside their four-unit building during a March 2016 rampage.

He prosecuted Dariaz Higgins, who ultimately pleaded guilty in the 2019 killings of his 2-year-old daughter in Minnesota and her mother in Milwaukee. Higgins shot another woman in the incident, who survived. Higgins was sentenced to life in prison.

Tiffin successfully prosecuted Elias Alvarado and Angel Guichardo, the two men who fatally shot Teryton Bonner outside a Milwaukee gas station in February. They wanted to rob Bonner of his pistol.

Judge David C. Swanson

David C. Swanson graduated from Northwestern University in 1985 before receiving his law degree from the University of Michigan in 1995.

Swanson was elected to the Milwaukee County Circuit Court in 2013. He was re-elected in 2019. Before his election to the bench, Swanson was an attorney at the Whyte Hirshboeck Dudek S.C. law firm in Milwaukee. Swanson also served commissioner for the Wisconsin Tax Appeals Commission from 2005 to 2011. Before that, he was an associate with two other firms — Godfrey & Kahn, S.C. (1995-98) and Quarles & Brady LLP (1998-2005).

Here are other key witnesses who may testify during the trial

Dr. Brian Peterson, former Milwaukee County Medical Examiner: He performed the autopsy on Acevedo. His departure from the office in 2022 had a domino effect on several cases, including Mattioli's.

Sara Schreiber, Milwaukee County Medical Examiner's Office: She's expected to testify about toxicology test results that were conducted on Acevedo. Those results, Mattioli's defense team argues, will reveal Acevedo had alcohol, cocaine metabolites and THC metabolites in his system at the time of the incident.

Sandra Koresch, Wisconsin State Crime Lab: Defense attorneys want to question her about her analysis of residue found on a dollar bill recovered from the scene. It tested positive for cocaine.

Pamela Taylor, Wisconsin State Crime Lab: She's expected to testify about her analysis of DNA swabs taken from the cocaine-saturated dollar bill indicated a "mixture of DNA" from Acevedo and another man, while excluding Mattioli.

Dr. James L. Pearle: Based in California, the pulmonologist is expected to testify that Acevedo's existing chronic respiratory disease played a role in his death.

This article originally appeared on Milwaukee Journal Sentinel: Who's who in the Michael Mattioli homicide trial