Witchcraft was a capital offence according to Han laws, especially if it involved noble families. Empress Chen's association with Chu Fu was soon discovered, and Emperor Wu assigned the infamously feared prosecutor Zhang Tang (張湯) to investigate. After Zhang's massive crackdown, Chu Fu was arrested and executed by decapitation, along with more than 300 other accused individuals. Emperor Wu then issued an edict officially deposing Empress Chen from the position of empress in 130 BC, and exiled her out of the capital Chang'an and placed her under house arrest at the Long Gate Palace (長門宮), a suburban household that Princess Guantao once offered to Emperor Wu as a gift for tolerating her private scandals, although Emperor Wu had promised her aunt that the ex-empress would be supplied with all the daily living necessities.