One of Gov. Robert L. Ehrlich Jr.'s key legislative priorities got a testy reception yesterday from a Senate committee chairman who questioned the governor's proposal to adopt a popular anti-gun crime program used, and widely praised, for years in Richmond.

State Sen. Brian E. Frosh (D-Montgomery) accused supporters of Ehrlich's proposed Project Exile of committing "a common logical fallacy" by crediting Richmond's recent dramatic drop in homicides to that city's Project Exile program.

He pointed to a recent study showing that a dramatic decline in homicides in Richmond would have occurred without the program and that Project Exile received credit because it was enacted about the same time as the drop.

"Your theory is that it's going to have an impact, and there is at least one study that says it [Project Exile] doesn't work," Frosh told Ehrlich's deputy legislative officer, Donald J. Hogan Jr., during a hearing before the Senate Judicial Proceedings Committee. "If you're going to make a major policy change, there needs to be something more behind it than 'Well, this might work.' "

Testifying in favor of the bill yesterday was an array of police officials and prosecutors, including Montgomery County State's Attorney Douglas F. Gansler (D), Prince George's State's Attorney Glenn Ivey (D) and Edward T. Norris, superintendent of the Maryland State Police.

"Maryland continues to have the highest rate of gun-related crime in the country," Norris told the committee. "There's a whole lot of illegal guns out there, and I think we would benefit tremendously from this bill."

Criticized by gun-control advocates during last fall's campaign, Ehrlich (R) responded with a promise to take gun-toting criminals off the streets in a program similar to Richmond's. Project Exile relies on mandatory minimum five-year sentences for felons caught carrying guns and encourages federal prosecution of such crimes.

Last month, Maryland U.S. Attorney Thomas DiBiagio said his office would take on prosecution of more gun crimes in Prince George's County and Baltimore to help Maryland implement Project Exile.

The legislation would set the sentencing requirements and forbid judges to reconsider the sentences.

That ban on reconsideration has drawn criticism from Frosh and other lawyers.

Frosh cited a study, released in January, by professors at the University of California at Berkeley and Georgetown University that concluded that Richmond's Project Exile was not responsible for a 30 percent decrease in that city's gun-related homicides in the 1990s.

Hogan told Frosh that he has no data suggesting that the January study was wrong, but he said that it would be too early for any counter-studies to be finished.