from the case in May. Alvarez, who lost her re-election bid in March, is leaving office in November.

“This is a very important case involving serious allegations,” read part of a statement issued by McMahon’s office, noting he can’t comment on any aspect of the evidence or offer opinions on the case. “We have one goal in this case, and that’s to present the truth in court and seek justice.”

Other members of McMahon’s legal team are Marilyn Hite Ross, first assistant state’s attorney in Winnebago County; Kane County First Assistant State’s Attorney Jody Gleason; and Kane County Assistant State’s Attorneys Joe Cullen and Dan Weiler.

Van Dyke faces 20 to 60 years in prison if convicted; a different special prosecutor has been appointed to investigate whether other officers were part of a cover up. Van Dyke, who is free on bail, is next due in court Aug. 18.

McMahon , a father of three who insists on being called “Joe,” was appointed state’s attorney in late 2010 after his predecessor became a judge. McMahon has developed a reputation for being thoughtful and thorough, tough but fair.

He graduated from St. Edward High School in Elgin in 1984, received his bachelor’s degree from the University of Iowa in 1988 and completed John Marshall Law School in 1992.

McMahon worked as an intern in 1991 at the Kane County state’s attorney’s office, eventually becoming chief of the criminal division by 1998. At the end of 2000, he left Kane County to work for the Illinois attorney general’s office as deputy chief of criminal prosecution. Later, McMahon joined Hinshaw & Culbertson, a national firm with offices in Chicago and Lisle, eventually forming his own firm with Richard Williams in Geneva.

During his six years as Kane County’s top prosecutor, he has placed an emphasis on prevention and education while stressing that violent perpetrators and career criminals should be severely punished. McMahon is seeking his second full 4-year term in November. In announcing his re-election bid, McMahon said he’s made fighting violent crime a priority, and he also has supported programs that sentence first-time or nonviolent offenders through a variety of diversion and treatment programs.

A study showed that 92 percent of the people — or essentially 11 out of 12 — who completed the county’s pretrial diversion program for first-time, nonviolent felony offenders have not been arrested in at least three years. McMahon’s office also has prosecuted police officers on an array of felony charges. Some examples:

• In May 2011, McMahon announced misconduct charges against Elgin police officer Michael Sullivan, accused of planting a cellphone on a robbery suspect in an effort to get promoted. Sullivan resigned from his job, pleaded guilty to misdemeanor obstruction of justice and was sentenced to a month in jail, 24 months’ probation and 200 hours of community service.

• In spring 2013, McMahon’s office charged former Elgin Deputy Police Chief Robert Beeter with hacking into the email of his mistress’s husband to help her with her divorce. Beeter also was charged with using a law enforcement database for personal use. He pleaded guilty to felony identity theft in July 2015 and was sentenced to two years probation and 50 hours of community service.

• In January, McMahon prosecuted the former leader of the Elgin Police Explorer post who was charged with felony theft and misconduct. James Rog, an animal control officer for Elgin police for 14 years, pleaded guilty in June to the reduced charge of misdemeanor theft, paid $6,000 in restitution to the city and was ordered to seek treatment for gambling addiction.

McMahon also has acknowledged mistakes. In March 2012 he and then Aurora Police Chief Greg Thomas moved to set aside the first-degree murder conviction against Jonathan Moore, then 19 and convicted of gunning down a Montgomery man in August 2000. Moore, who has since changed his last name, was sentenced to 75 years in prison. But McMahon’s office and Aurora police investigated further after a witness came forward with details about the crime unknown to the public.

McMahon said then the decision reflected a duty “to assess new information that may cast serious doubts about those convictions. Nobody wants to see the guilty go free, but it is just as important that those who are not guilty do not sit in prison. Finding that balance can pose one of the biggest challenges I face.”

• Daily Herald news services contributed to this report.