A death row inmate convicted of setting a fire that killed five children must be released or retried because his constitutional rights were violated when his confession was used at trial, a federal appeals court panel ruled Tuesday.

The 6th U.S. Circuit Court of Appeals judges ruled 2-1 that William Garner didn't understand his right to silence when he told police he would waive his Miranda rights against self-incrimination. He gave a taped statement to police, saying he set fire to a Cincinnati apartment with six children inside to destroy evidence of his burglary, according to court records.

Garner told police he thought the children would be awakened by the smoke and escape, according to court records. Only one child survived, and Garner, now 34, was convicted of five counts of aggravated murder in the 1992 fire, along with arson and other charges.

Judge Karen Nelson Moore, joined by Judge Boyce L. Martin, wrote that evidence showed that Garner, 19 at the time of the statement, was poorly educated and had low intelligence and other limitations directly related to understanding and comprehending his rights. Expert testimony also showed that Garner didn't understand the word "right" or his right to remain silent, their opinion stated.

"Thus, admission of his statement at trial was unconstitutional," the opinion stated.

Judge John M. Rogers dissented, saying police repeatedly asked and obtained assurance that Garner understood their meaning.

The judges granted Garner's request for habeas corpus, which protects inmates from unlawful imprisonment, and ordered his release in 180 days unless the state sets a new trial.

The state could ask for the case to be heard by all 14 appeals court judges or appeal to the U.S. Supreme Court.

Messages seeking comment were left with Attorney General Marc Dann's office.

Kyle Timkin, an assistant state public defender who argued Garner's case, said he was trying to reach his client, who is being held at the Mansfield Correctional Institution.

"Obviously, we're thrilled," he said. "It just basically affirms long-standing principles."