ATMORE, Ala. - Thirteen minutes into his execution by injection, an Alabama inmate heaved and coughed and appeared to move during tests meant to determine consciousness.

Forty-five-year-old Ronald Bert Smith Jr. was finally pronounced dead at 11:05 p.m. Thursday night - about 30 minutes after the procedure began at the state prison in southwest Alabama.

Alabama uses the sedative midazolam as the first drug in a three-drug lethal injection combination. Smith and other inmates argued in a court case that the drug was an unreliable sedative and could cause them to feel pain, citing its use in problematic executions. The U.S. Supreme Court has upheld the use of the drug.

Smith was convicted of capital murder in the Nov. 8, 1994, fatal shooting of Huntsville store clerk Casey Wilson.