The job listing says:
As a Special Agent you will combine your accounting skills with law enforcement skills to investigate financial crimes. Special Agents are duly sworn law enforcement officers who are trained to “follow the money.” No matter what the source, all income earned, both legal and illegal, has the potential of becoming involved in crimes which fall within the investigative jurisdiction of the IRS Criminal Investigation. Because of the expertise required to conduct these complex financial investigations, IRS Special Agents are considered the premier financial investigators for the Federal government.
Read more: IRS Job Listing: Special Agents Must ‘Carry a Firearm and Be Willing to Use Deadly Force’