Tolleson, outside Phoenix, has filed an amicus brief in the Justice lawsuit, which will go to the 9th U.S. Circuit Court of Appeals on Nov. 1, The Arizona Republic reported Sunday.
The city made the move after a federal judge in August dismissed a lawsuit by a Tucson police officer who charged Senate Bill 1070 was unconstitutional. Tolleson joined that suit.
Phoenix attorney Jose de Jesus Rivera told the city council last week that Tucson, Tolleson and the other cities he represents are not sanctuary cities but that SB 1070 seeks to make cities an arm of immigration enforcement.
"In fact, it takes your resources away from other crimes," Rivera told the council, adding that under SB 1070, anyone who believes the city isn't following the law can sue the city.
The brief asserts that "if the key provisions of Arizona Senate Bill 1070 are revived on appeal, those revived provisions will impose expensive, unwieldy, and unconstitutional requirements."
Tolleson Mayor Adolfo Gamez has said SB 1070 will lead to racial profiling.