HB 1645 creates a private civil cause of action against local entities or campus police departments that adopt policies in violation of state laws related to immigration enforcement. It allows individuals injured, or personal representatives of individuals killed, by someone unlawfully present in the United States to sue the responsible local entity or campus police department if their failure to comply with immigration enforcement laws enabled the crime to occur. The bill explicitly waives sovereign and governmental immunity to the extent of this liability. Courts may award damages, reasonable costs, and attorney’s fees to prevailing parties. The Act applies only to causes of action that accrue on or after September 1, 2025, its effective date.