This involves racketeering, and certain prosecutions under (1) RICO laws b/c it involves patterns of criminal behavior, and, (2) the Hobbs Act---b/c communities are economically undermined, expected to provide limitless govt handouts to non-citizens.
REFERENCE SOURCE justice.gov---Criminal Resource Manual ---Section 9-131.000---THE HOBBS ACT18 U.S.C. § 1951
The Hobbs Act (18 U.S.C. § 1951) prohibits actual or attempted robbery or extortion affecting interstate or foreign commerce. Section 1951 also proscribes conspiracy to commit robbery or extortion without reference to the conspiracy statute at 18 U.S.C. § 371. Although the Hobbs Act was enacted as a statute to combat racketeering in labor-management disputes, the statute is frequently used in connection with cases involving public corruption, commercial disputes, and corruption directed at members of labor unions (has been recently utilized against corrupt elected officials).
Primary investigative jurisdiction of offenses in 18 U.S.C. § 1951 lies with the Federal Bureau of Investigation. The Inspector General's Office of Investigations, Division of Labor Racketeering (formerly the Office of Labor Racketeering), United States Department of Labor, is also authorized to investigate violations of 18 U.S.C. § 1951 in labor-management disputes involving the extortion of property from employers by reason of authority conferred on investigators as Special Deputy United States Marshals.--snip--
Migrant crimes most probably include (1) falsifying official documents, (2) giving false info to US authorities, (3) stealing SS nos, (4) faking multiple identities, (5) receiving govt monies under false pretenses, (6)falsifying tax returns to get EITC refunds, (7) money-laundering via remittanced to homelands, (8) colluding w/ criminal drug cartels to violate US borders...perhaps aiding and abetting by carrying drugs into the US.