Virginia prosecutors are asking state lawmakers to eliminate a law that they say has hampered their ability to win convictions of some confessed suspects.

Under that law, testimony given by a defendant at a criminal trial other than his own may not be used against him. Robert F. Horan Jr., head of the Virginia Association of Commonwealth's Attorneys, said his group wants to change the law to permit use of such testimony.

The testimony law is "really peculiar," said Horan, Fairfax County's chief prosecutor. "We don't really see any logic in it. In a couple of cases it's really been tough to convict people that confessed at someone else's trial."

Horan said the most notorious example was a 1973 Augusta County case that involved two Staunton brothers charged with robbing and maliciously wounding another man.

Franklin D. Cale confessed to the crimes at the trial of his brother, John D. Cale, but almost escaped conviction when prosecutors were barred from introducing his statement at his trial, Horan said.

John Cale was convicted and sentenced to 22 years in prison and his brother Franklin was given 24 years on the strength of evidence other than his own statement.

Other changes the prosecutors are recommending to the 1982 General Assembly would allow use of court-approved wiretaps in some marijuana and gambling cases; add two years to the penalties given to individuals who use a firearm during the commission of a felony and bar that person from being paroled; institute two-part trials in rape, murder, robbery and burglary cases so the jury would be aware of a defendant's record before recommending a sentence. Under Virginia law juries recommend sentences for individuals whom they convict.

The prosecutors' proposals will be reviewed by the State Crime Commission and then forwarded to the legislature, which convenes in mid-January.