In 2006, Officer Dean Vincent signed up for the city's life insurance program, according to attorney Keith Hunt, who is representing Susan Vincent.
The policy was supposed to pay out $300,000.
After Vincent died last year, his widow says she found out the life insurance company was paying only $100,000.
"When Susan first met with human resources after Dean died, they opened up the file and there were all the forms filled out showing that he had applied for a $300,000 policy," said Hunt.
The City of North Chicago responded to a request for a statement by saying, "We've referred this matter to the city's insurance carrier. They are reviewing the complaint."