Sergeant John Pallohusky was president of the Chicago Police Sergeants Association. He was arrested in 2009 after a bank noticed suspicious activity in the union's account.
Prosecutors say Pallohusky wrote checks from the union's accounts to himself totaling more than $600,000. They say he used the money to pay for a home and trips to Las Vegas.
Pallohusky will be sentenced June 1. He faces up to 15 years in prison.
