Mass deportations effectively deter the violent El Salvadoran MS-13 gang from expanding across the United States, an investigation finds.

Research conducted by the State of New Jersey Commission of Investigation found that mass deportations of illegal aliens, which took place in the 1990s and 2000s, helped deter the expansion of the MS-13 gang across the U.S.

The report reveals:

In the 1990s and through the 2000s, law enforcement sought to counter MS-13’s growing influence by enlisting U.S. immigration authorities to deport tens of thousands of immigrants who had been convicted of crimes in the United States [emphasis added]. The strategy proved a stopgap solution. While it initially diminished MS-13 in California, it exported the gang’s culture to Central America, where deep poverty and corruptible law enforcement agencies allowed the gang to flourish [emphasis added].

The study also notes that mass immigration to the U.S. — where more than 60 million immigrants have arrived since 1965 — helped the MS-13 gang grow in membership and size, now spanning across 40 states with more than 10,000 members.

“Migration, both within the United States and from Central America to the United States, contributed to the gang’s spread through the 1990s and 2000s,” the report states. “MS-13 established beachheads in Texas, Charlotte, N.C., Washington D.C., Virginia, Maryland, New Jersey, Long Island, and Massachusetts. Numerous cliques are now entrenched in these strongholds, fed by the recruitment of teens and young men.”

Other deterrents of the MS-13 gang exists. The research found that cooperation between the Immigration and Customs Enforcement (ICE) agency and local law enforcement agencies — the opposite of sanctuary city laws — aid in arresting, prosecuting, and deporting violent MS-13 gang members.

“Visible MS-13 activity in New Jersey has waned considerably in the past three years, the result of aggressive prosecutions at the state and federal levels and a close partnership with ICE,” the report notes. “Dozens of MS-13 members now sit in prison for crimes that include racketeering, conspiracy, and murder.”

Most recently, six MS-13 gang members — four of whom are illegal aliens — were accused of butchering to death a 17-year-old Massachusetts boy. One of those MS-13 gang members successfully convinced an immigration judge that he was not affiliated with the gang.