A federal judge says the state of Massachusetts must provide a sex-change surgery for an inmate serving a life sentence for murder.

Michelle Kosilek, born Robert, was convicted of murdering his wife, Cheryl, in 1990. He received hormone treatments and is now living as a woman in an all-male prison.

U.S. District Judge Mark Wolf ruled the surgery is the only to treat Kosilek's "serious medical need." Wolf is the first judge to order sex-change surgery as treatment for "gender-identity disorder."

Sen. Scott Brown, D-Mass., denounced the ruling, calling it "an outrageous use of taxpayer dollars."

"We have many big challenges facing us as a nation, but nowhere among those issues would I include providing sex-change surgery to convicted murderers," Brown said in a statement. "I look forward to common sense prevailing and the ruling being overturned."