The handcuffs around Joseph C. Frady's wrists were unlocked at 10:42 a.m. yesterday in U.S. District Court and he became a free man 17 years after he was sentenced to death for the brutal killing of a Southeast Washington man who was bludgeoned with a table leg.

In a decision last August that still rankles some judges and prosecutors, the U.S. Court of Appeals said that District Judge George L. Hart Jr. who presided at Frady's trial in November 1963, had given the jury legal instructions that were later declared improper.

Frady, a muscular, blond man who is now 43 years old, stood before Hart again yesterday. The appeals court had directed Hart to release Frady from prison -- he would have been elgible for parole in 1983 -- while the Justice Department decides whether to take his case to the U.S. Supreme Court.

In a stern voice, Hart said that the crime for which Frady and a codefendant were convicted was "perhaps without question the most brutal murder that has ever been before this court."

Frady and his codefendant were found guilty of first-degree murder and sentenced to die in the electric chair. They spent two years on death row before their sentence was commuted to life in prison.

Frady befriended a fellow inmate who devised a legal theory that, along with help from a student and a professor from the Georgetown Law Center, gave Frady his long-sought freedom. That inmate was Michael (Miami Mike) Kleinbart, an accomplished jailhouse lawyer, serving time for shooting two U.S. Park Police officers at the Jefferson Memorial in 1975. s

The appeals court said last summer that while the instructions that Hart gave to the jury in 1963 were acceptable then, they were ruled improper five years later by another court because they eliminated the chance that the jury could have found Frady guilty of the lesser crime of manslaughter instead of murder. Coupled with another decision in the 1970s, which said that a verdict could be overturned if it was seriously tainted by improper jury instructions, the appeals court last summer reversed Frady's conviction.