The attorney for a man who was executed this week is calling for an investigation, accusing Missouri officials of moving ahead with the lethal injection while federal appeals were pending.

Raheem Taylor, 58, was executed Tuesday night for the 2004 deaths of his girlfriend and her three children in suburban St. Louis.

Taylor claimed he was out of state when the family was killed. Investigators don’t deny he was in California when the bodies were found but a medical examiner determined the victims had died up to three weeks earlier — at a time when Taylor was still in Missouri.

The innocence claim was turned aside repeatedly in the days leading up to the execution. St. Louis County Prosecuting Attorney Wesley Bell, a Democrat, declined to ask a judge for a new hearing, stating the “facts are not there to support a credible case of innocence.”

Republican Gov. Mike Parson denied clemency, saying evidence showed that “Taylor committed these atrocities and a jury found him guilty.” The Missouri Supreme Court declined to grant a stay on Monday, and the U.S. Supreme Court did the same about two hours before the execution.

While appeals over Taylor’s claims of innocence had been exhausted, Taylors attorneys asked a federal appeals court and the U.S. Supreme Court for a stay because Taylor’s spiritual adviser, Anthony Shahid, was not allowed to be in the execution room.

A Supreme Court decision last year allows inmates to have spiritual advisers near them at executions. The appeal also questioned why two lawyers who supported Taylor couldn’t witness the execution.

“It was being appealed at the time they killed him,” Kent Gipson, an attorney for Taylor, said Thursday. “And although there technically wasn’t a stay in place, they’ve never done this before — this has never happened before in almost 100 executions. That’s what’s disturbing about it.”

Taylor’s lawyers urged an internal investigation by the Missouri Department of Corrections and investigations by “other law enforcement agencies.”

Madeline Sieren, spokeswoman for Missouri Attorney General Andrew Bailey, said there was no reason not to move ahead with the execution.

“As there was no stay in place, the Attorney General’s Office fulfilled its legal obligation to notify the Governor’s Office and the Department of Corrections at the appropriate time that there was no legal impediment to carrying out the execution warrant set forth by the Missouri Supreme Court,” Sieren said in a statement on Thursday.

Missouri Department of Corrections spokeswoman Karen Pojmann said Taylor initially declined to have Shahid with him for the execution. He changed his mind over the weekend but by then it was too late to change the witness list because the prison needs time to conduct background checks, Pojmann said. The lawyers also sought approval to be witnesses too late, she said.