MONTGOMERY, Ala. (AP) — Alabama told a federal judge that it could soon be ready to use a new, untried execution method called nitrogen hypoxia to carry out a death sentence.

The disclosure came Monday at a court hearing over inmate Alan Miller's request to block his scheduled Sept. 22 execution by lethal injection. Miller maintains that prison staff lost paperwork he returned in 2018 requesting nitrogen hypoxia, an execution method that the state has authorized but never used.

U.S. District Judge R. Austin Huffaker Jr. asked whether Alabama was ready to carry out executions by nitrogen hypoxi...