While her husband and daughters were out of state, Dr. Teresa Sievers was murdered. 'This was almost the perfect crime,' says prosecutor Cynthia Ross. 'There was absolutely no trace evidence.'

Working as an informant for the FBI is dangerous, undercover work. Hear from writer Jeanette Hurt on how her dad, an unexpected FBI informant, helped expose corruption at the Chicago Truck Drivers, Helpers and Warehouse Workers Union.

Dominick Polifrone gained the confidence of the contract killer in an undercover operation that almost cost him his life.