Story highlights Death row inmate Mark Asay was denied a stay of execution by US Supreme Court

Florida executes Asay for killing two men in 1987

(CNN) Florida executed an inmate for the first time in more than 18 months, administering a lethal injection drug that had not previously been used in the United States.

Mark Asay, 53, was executed at 6:22 p.m. ET on Thursday without any incident, Florida corrections officials said.

Asay had no last statement, and did not speak or show any indication of pain during the execution. His demeanor earlier in the morning was calm, a Florida corrections department spokeswoman said.

Thursday afternoon, the US Supreme Court denied a stay of execution request for Asay.

Asay was convicted in 1988 of the racially motivated murders of two men in Jacksonville the previous year.