Healing Heroes Network has a mission that tugs at the heartstrings: providing financial assistance to veterans of Iraq and Afghanistan so they can get critical medical care. But the nonprofit based in Palm Harbor, Fla., also raises a few red flags for donors.

To see how telemarketing companies target donors, the Tampa Bay Times and The Center for Investigative Reporting focused on one company, Associated Community Services, and examined how it did business in one state, Iowa.

Police Protective Fund raises millions of dollars each year in the name of fallen officers. Now, four men in charge of the charity’s telemarketing operations have been arrested on charges of hiring felons to raise that money.

America’s worst charities have come under renewed scrutiny following a series by the Tampa Bay Times and The Center for Investigative Reporting that ranked organizations based on how much they spent on professional solicitation companies over the past decade.