A former executive at Mayer Brown just got busted for embezzling nearly $1 million from the Chicago-based law firm.

Yesterday, the FBI arrested 51-year-old David Tresch, Mayer Brown’s former chief information officer, at his Chicago-area home on charges that he stole more than $850,000 from the law firm in the past year.

Tresch worked at Mayer Brown in a variety of positions from May 2004 until June this year, when the firm fired him after an internal investigation into suspicious payments he made to an IT vendor. Mayer Brown alerted the authorities and cooperated with federal prosecutors on a government investigation into Tresch’s activities.

The government’s complaint alleges that Tresch approved $980,000 in payments to an IT vendor for work that hadn’t been performed between May 2011 and May 2012, and the vendor sent him checks totaling $854,250. Mayer Brown paid the IT vendor almost $8 million between November 2004 and March 2011.

The Wall Street Journal Law Blog says Tresch spent his illegal proceeds on a fleet of vehicles, including a 2011 Cadillac DTS, an RV camping trailer, a work van and a mobile home.

Read the Chicago Tribune for more about the Mayer Brown CIO scandal.