Three months after pleading guilty to driving under the influence of alcohol, a former top federal prosecutor in Illinois has left Armstrong Teasdale's headquarters in St. Louis.

A spokeswoman for Armstrong Teasdale confirmed to The American Lawyer that partner Stephen Wigginton had recently left the Am Law 200 firm's ranks, but did not have new contact information for him. An email sent to Wigginton through a lawyers' referral service was not returned by the time of this story.

Curtis Dawson, a name partner at Edwardsville, Illinois-based Lucco, Brown, Threlkeld & Dawson who represented Wigginton in his DUI case earlier this year before a court in Madison County, Illinois, also did not return a request for comment about his client.

Wigginton served from August 2010 to December 2015 as U.S. attorney for the Southern District of Illinois, where the U.S. Department of Justice has regional offices in the Illinois cities of Benton, East St. Louis and Fairview Heights. Wigginton joined Armstrong Teasdale nearly two years ago as a litigation partner specializing in commercial class action and whistleblower cases.

In late May, he was arrested and charged with fleeing the scene of an accident in the St. Louis suburb of Troy, Illinois. Wigginton reportedly said, “You know who I am,” to a police officer that eventually stopped him, according to a dashboard camera video obtained by local news outlets under the Illinois Freedom of Information Act. When the officer said he didn't know who Wigginton was, the now former Armstrong Teasdale partner replied, “Your boss does.”

Wigginton, who in the police dashcam video said he had a “glass of vodka” while out with clients, was unable to complete a field sobriety test. He initially pleaded not guilty, but subsequently accepted a deal from prosecutors that dropped two charges against him and resulted in Wigginton pleading guilty to a standard DUI charge on July 11. He agreed to pay a $1,500 fine, double the normal sum for such an infraction.

According to records on file with the state bars of Illinois and Missouri, Wigginton is in good standing and has no instances of attorney discipline. His departure from Armstrong Teasdale comes the same month that the firm had sanctions against it lifted in a putative class action case against FCA US LLC, the Auburn Hills, Michigan-based automotive giant better known as Fiat Chrysler, as noted last week by legal newswire Law360.

Wigginton and several other Armstrong Teasdale lawyers are representing a class of Jeep Cherokee owners suing FCA and audio equipment company Harman International Industries Inc.—represented by Thompson Coburn and Foley & Lardner, respectively—over an optional communication device called Uconnect that they claim allows hackers to seize control of their vehicles. Armstrong Teasdale and Wigginton ran into trouble in April when FCA successfully sought sanctions against the firm for quoting from sealed documents in the case in another action filed in Northern California.

Earlier this month, a federal judge in East St. Louis responded to a request by Wigginton and sealed a motion to certify a class action against FCA, according to The Madison County Record. Brian Flynn, a name partner at Belleville, Illinois-based Flynn Guymon & Garavalia serving as a lead plaintiff in the suit against FCA and Harman, did not immediately return a request for comment about whether or not Wigginton is still representing him in the litigation, which was filed in August 2015.

Wigginton is listed in court filings—the most recent of which is dated Nov. 17—as working at Armstrong Teasdale. A firm spokeswoman said that Wigginton is still listed on documents from cases that were in progress during his time at Armstrong Teasdale.

As for the firm itself, Armstrong Teasdale has offset the recent departure of Wigginton with two lateral hires, among them Stinson Leonard Street real estate and financial services partner Joseph Hipskind Jr. in St. Louis and Dickinson Wright litigation partner Michelle Alamo in Denver.