Hundreds of protesters spoke out Thursday at an annual May Day rally against Dane County Jail’s collaboration with Immigration and Customs Enforcement, which has led to dozens of deportations of undocumented immigrants over the past year.

Supporters from both the University of Wisconsin and Dane County marched from Brittingham Park to the City-County Building at 210 Martin Luther King Jr. Blvd.

Protesters sang, played instruments and repeatedly chanted “S? se puede,” Spanish for “Yes we can.”

In response to the protest, Dane County Sheriff Dave Mahoney said Dane County Jail routinely fills out a booking sheet asking for personal information, which includes the question of citizenship status and place of birth. If an individual self-identifies as a non-United States citizen, it is the responsibility of Dane County Jail as a law enforcement agency to cooperate with other federal or local agencies, Mahoney said.

Alex Gillis, spokesperson for the Immigrant Workers Union, said Dane County Jail’s inquiries about citizenship status during the arrest process have led to unwarranted deportations of undocumented immigrants. Gillis added it is not the responsibility of Dane County Jail to inquire about migratory status because immigration laws are not under local jurisdiction.

“The specific issue that we want to bring to the eye of the public is that we think what Dave Mahoney is doing right now is the biggest offense to human rights in the last 20 years,” Gillis said. “We are demanding for him to stop it. He is not obligated to do it.”

Out of 1,300 bookings in the month of January, the Dane County Jail made 25 notifications to ICE, eight of which resulted in undocumented immigrants being held at the Dane County Jail until ICE either dropped the warrant or picked the individuals up to be deported.

Although Mahoney said he is compelled to notify ICE when individuals are arrested or charged for a criminal offense, he said when ICE has requested Dane County Jail to participate in the execution of raids or warrants to “round-up” undocumented immigrants, he has declined.

“Neither I nor any other officer from Dane County Jail have been involved in the deportation of undocumented immigrants,” Mahoney said. “When asked to participate, we have taken the position that we will not.”

Janet Parker, co-chair of Wisconsin Network for Peace and Justice, said Dane County Jail plays a key role in the deportations of dozens of undocumented immigrants.

“Right here in Madison we are seeing a stark spike in raids by ICE,” Parker said. “Our sheriff’s office has been acting as an enforcement arm for ICE, and we come here today to ask the sheriff to stop collaborating.”

Nearly 30 UW students rallied at Library Mall before walking to Brittingham Park to join the larger protest, and many voiced their disappointment about the lack of immigrant rights in the United States.

“Only in places like this are immigrants the most exploitable. They have the most to lose. Only in places like these can workers of any type, especially immigrants, find their voice,” said John Bruning, UW sophomore and Student Labor Action Coalition member. “Only in crowds, only in rallies and marches like today can they really have a voice.”