A judge on Monday found Brooklyn City Councilman Jumaane Williams guilty of blocking an ambulance at a rally for immigration activist Ravi Ragbir.
The incident happened in January.
Ragbir had been issued a final deportation order to his native Trinidad before he was taken away by immigration and customs agents.
Williams was sentenced to time served for blocking the ambulance that Ragbir was riding in after he fainted.
"I'm hoping more people will have the courage to step out so maybe we don't have these instances again," Williams said.
"Because they slowed that ambulance, a federal judge had the opportunity to rule on the legality of Ravi Ragbirs detention while he was still in the United States before ICE had an opportunity to exile him," said Williams' attorney.
Sixteen others were arrested, including Manhattan City Councilman Ydanis Rodriguez who pleaded guilty to disorderly conduct.