John A. Wasilenko, 39, of Norridge, was taken into custody Friday morning. He is charged with official misconduct and financial exploitation of a senior citizen.
Police say they were contacted by an elderly man who said he did not write a $20,000 check that was made out to Wasilenko. Investigators say Wasilenko deposited a check in that amount in December 2012.
Police say the victim is an 84-year-old man with advanced dementia, whom Wasilenko allegedly befriended after speaking to the victim about thefts at his Elmwood Park home.
He is scheduled to appear in bond court Friday.