<a href="mailto: dvsavini@cbs.com; mhlebeau@cbs.com; mayoungerman@cbs.com" target="_blank">Send Your Tips To Dave Savini</a>By Dave Savini

(CBS) — How did a police officer remain on the job and in a command position despite repeated allegations of corruption?

The 2 Investigators first reported on Sgt. John Wasilenko last year. Now, he allegedly preyed on a senior citizen with a disability.

CBS 2 reporter Dave Savini’s investigation has already prompted action.

Eighty-five-year-old Angelo Ditore is suffering from dementia — and financial exploitation. He was found living in an empty, bedless apartment in Elmwood Park in December 2012.

Ditore — now a ward of the state and the Cook County Public Guardian — was allegedly ripped off by a police sergeant from Elmwood Park.

If Sgt. John Wasilenko’s name sounds familiar, it should. The 2 Investigators exposed how he was suspended and disciplined for other wrongdoing in February 2013.

Wasilenko allegedly used police resources to follow, harass and run illegal background checks on three men in Elmwood Park after he got involved with their estranged wives or girlfriends during domestic-related police calls.

After his suspension back then, in September 2012, police officials gave him his old job back and he kept his rank as a sergeant. One month later, he met the ailing Ditore on a police call for help.

Ditore went to the Elmwood Park Police Department in October 2012 in need of police assistance after he believed he was burglarized.

Wasilenko responded after Ditore reported $70,000 missing from the Elmwood Park apartment building Ditore owns on North Avenue.

No one was ever arrested, but two months later, Wasilenko ended up cashing a $20,000 check written in his name from Ditore’s bank account.

“We know there was a check written for $20,000, and then there’s some talk about some other monies,” says Cook County Public Guardian Robert Harris.

Harris is suing Wasilenko for financially exploiting Ditore, who is now in a nursing home with around-the-clock care.

Wasilenko refused to talk to CBS 2 when asked about the $20,000 check, but he allegedly told police investigators from Brookfield, where Ditore’s bank was located, that he ran errands for the elderly man and the check was a “gift.”

But Elmwood Park Police Chief Frank Fagiano says: “It’s against policy for police officer to receive any kind of gratuity from citizens.”

Harris says Wasilenko exploited Ditore and used his position as a police sergeant to gain Ditore’s trust and then victimized him.

“Mr. Ditore went to the police to get help because he thought he was being ripped off, and the folks that are supposed to be protecting him ended up harming him,” Harris says.

Wasilenko remained on the job for a full year until CBS 2 informed his bosses last week that the station has a copy of the check and that the public guardian has filed suit.

Wasilenko was then put on administrative leave, pending an internal investigation.

Fagiano, the police chief, says he left Wasilenko on the job after learning about the new allegations in December 2012 because he did not want to “jeopardize criminal investigations by the Cook County State’s Attorney Office and the Cook County Sheriff’s office.”

Both of those agencies would not comment.