The law that makes it a federal offense to be directly or indirectly involved in a pattern of criminal activity is the:

The RICO Act, or the Racketeer Influenced and Corrupt Organizations Act, is legislation designed to combat organized crime in the United States by allowing prosecution and civil penalties for racketeering activities. It targets a pattern of illegal activity carried out as part of an ongoing criminal organization, making it a federal offense to be involved in such activities, whether directly or indirectly.

Under the RICO Act, individuals can be charged not only for their direct criminal behavior but also for promoting or facilitating the criminal activities of an organization or group. This broad definition allows law enforcement to address complex criminal enterprises more effectively.

In contrast, while the Fraud Enforcement and Recovery Act and the Organized Crime Control Act also deal with criminal activity, they do not specifically address the broader pattern of racketeering as the RICO Act does. The Criminal Justice Act, on the other hand, primarily focuses on the provision of legal defense for those who cannot afford an attorney, rather than directly addressing issues of criminal activity and racketeering. Thus, the RICO Act is the most fitting answer to the question regarding federal offenses related to involvement in a pattern of criminal activity.