NASHVILLE, Tenn. (AP) — A lawsuit challenging the right of the Davidson County Sheriff's Office to enforce federal immigration law can be expanded to also target the federal immigration agency, a federal judge has ruled.

Nashville immigration attorney Elliott Ozment is suing the Davidson County Sheriff's Office on behalf of three Nashville residents affected by the 287(g) program, which allows deputies to work with federal agents to investigate the immigration status of inmates.

Ozment argues the sheriff's office should not participate in the program because the agency gave up its law enforcement powers when the city and county consolidated in 1963. Under the charter, the sheriff's office is responsible for running the jail while the Metro Nashville Police Department is responsible for law enforcement in the county.

Ozment originally asked the Davidson County Chancery Court to issue an injunction barring the sheriff's office's participation in the federal program. The case was transferred to federal court after Chancellor Carol McCoy ruled that the federal Immigration and Customs Enforcement agency had to be added as a party to the dispute.

Attorneys for both Metro Nashville and ICE requested the case be dismissed.

In a ruling filed Tuesday, U.S. District Judge Kevin Sharp instead allowed Ozment to amend his complaint, adding a new plaintiff and claims of false imprisonment, violations of the federal Administrative Procedure Act and violations of the due process clause of the Fourteenth Amendment.

"That's why this was such an important victory," Ozment told The Tennessean newspaper. ..."We wanted to add federal causes of action. We were trying to solidify the claims against the federal government."

Ozment is seeking damages on behalf of a U.S. citizen of Mexican descent who was twice detained for days by the sheriff's office; a legal permanent resident from Honduras who was held for questioning about his immigration status; and a legal temporary resident from El Salvador whose son is in deportation proceedings because of 287(g).

Since Davidson County joined the federal program in 2007, immigrant rights advocates have complained that it encourages racial profiling and has caused many people to be deported after minor traffic violations rather than targeting serious offenders.

In May, Sheriff Daron Hall said the program may not continue if the number of immigrants detained continues to decline. Deportation proceedings for Nashville inmates have decreased 40 percent since 2008.