The Immigration and Customs Enforcement agency arrested 37 individuals accused of illegally entering the country during an operation over the weekend in Middlesex County, New Jersey.

Most of the targets of this investigation were illegal, criminal aliens who were apprehended and incarcerated at Middlesex County Jail and then released, even after ICE requested they be held.

Sixteen of the 37 people arrested had been released by the local jail while 78 percent, a total of 27 people, have prior criminal convictions or pending criminal charges. (RELATED: ICE: San Diego Chainsaw Attacker Is Illegal Alien Who Has Been Deported 11 Times)

“Middlesex County, which aspires to be a ‘sanctuary county’ by protecting criminal aliens, in the process assists criminals in undermining federal law and creates a dangerous environment in the community. It also overburdens local law enforcement. ICE will continue to execute its mission in such communities,” Ruben Perez, acting field office director of ICE’s Enforcement and Removal Operations branch in Newark, said in an ICE press release.

Perez took a shot at the county for their attempt to act like a “sanctuary city,” harboring potentially dangerous illegal immigrants.

One of the 16 people with a previous arrest and release apprehended during this operation was a 68-year old Mexican national who was originally in legal trouble surrounding a murder.

The man was sentenced to 25 years in prison after being convicted of aggravated manslaughter and for trying to hinder the prosecution. After an appeal, the manslaughter charge was overturned, and he was only found guilty of lying, which was still a felony. Even though ICE put a hold on him, he was released after being sentenced to time served.

These arrests come as ICE is facing intense scrutiny from the left. Many politicians have called for ICE to be abolished.