The Supreme Court seemed split Tuesday on whether to require police to read Miranda rights to prison inmates every time they interrogate them about crimes unrelated to their current incarceration.

The high court heard arguments from lawyers from the state of Michigan who want a federal appeals court decision overturning Randall Lee Fields' conviction thrown out.

Fields was serving a 45-day sentence in prison on disorderly conduct charges when a jail guard and sheriff's deputies from Lenawee County, Mich., removed him from his cell and took him to a conference room. The deputies, after telling him several times he was free to leave at any time, then questioned him for seven hours about allegations that he had sexually assaulted a minor. Fields eventually confessed and was charged and convicted of criminal sexual assault.

Fields was then sentenced to 10 to 15 years in prison but appealed the use of his confession, saying that he was never given his Miranda rights on the sexual assault charges.

On appeal, the 6th Circuit Court of Appeals in Cincinnati threw out his confession and conviction, ruling that it is required that police read inmates their Miranda rights anytime they are isolated from the rest of the inmates in situations where they would be likely to incriminate themselves.

This case is another example of the courts' recent struggle to clearly define Miranda rights, which have been litigated since they first came into being in 1966. The courts require police to tell suspects in custody they have the right to remain silent and the right to have a lawyer represent them, even if they can't afford one.

The tale of returned mail and a missed deadline might seem comical, if it did not involve a man trying to stave off execution. Supreme Court justices had harsh words Tuesday for lawyers who abandon their clients and a state legal system that does not seem overly concerned.

At the end of a lively hour of arguments, it appeared that the court would order a new hearing for Alabama death row inmate Cory Maples, who lost the chance to appeal his death sentence because of a mailroom mix-up at the venerable New York law firm Sullivan and Cromwell and the diffidence of a local court clerk.

Two Sullivan and Cromwell lawyers were pressing Maples' claim that his earlier legal representation was so bad that it violated the Constitution -- until they both left the firm without telling Maples or the Alabama courts.

Deadlines usually matter a lot at the Supreme Court, where a few years back a defendant who was late to file an appeal because the judge gave his lawyer the wrong date still lost his case. Another principle to which the court often holds dear is that it's tough luck for defendants whose lawyers make mistakes.

But Tuesday's case, perhaps because it involves the death penalty, was the rare instance when the court seemed prepared to grant some leeway on both counts.