Maryland Gov. Robert L. Ehrlich Jr. (R) yesterday came out against a proposal that would expand the state's ballistic-fingerprinting program to rifles and other long guns, citing concerns about the cost and effectiveness of the gun-tracking program.

Returning to an issue from last fall's campaign, Ehrlich spokesman Henry Fawell said the governor has "yet to be convinced" that the handgun database actually works and is considering whether it should be eliminated. After consultation with Ehrlich, Maryland State Police officials testified at a General Assembly hearing that the state should evaluate the system before spending more money to expand the program.

"We all want to solve crimes," said Lt. Col. Stephen T. Moyer, chief of field operations for state police. "But when we are one of only two states that is operating a system like this, the probability of a match is very small."

The ballistic-fingerprinting measure is part of a legislative package supported by gun-control proponents, who have received lobbying help from Montgomery County Police Chief Charles A. Moose and the mother of one of the victims of last fall's sniper shootings. Another bill considered yesterday would require gun owners to report lost or stolen weapons to police within 48 hours. A third would ban the possession or transfer of 45 types of assault-type weapons, a step that proponents say is needed because the Republican-controlled Congress could allow a federal assault weapons ban to expire next year.

Aimed at helping law enforcement officers find the owner of a gun used in a crime, ballistic-tracking systems such as Maryland's rely on the unique markings that each firearm makes on shell casings. A "fingerprint" taken before the gun is sold is scanned and entered into a computer database. Law enforcement officials can then compare the marks on a casing discovered at a crime scene against images on file.

Maryland currently requires the ballistic-fingerprinting of handguns sold in the state; the proposal Ehrlich opposes would expand that to include all firearms sold in Maryland.

Just two weeks ago, Ehrlich's superintendent of state police, Edward T. Norris, called ballistic fingerprinting "a great investigative tool for any police department." But yesterday, Norris's representatives questioned the program's effectiveness and the $2.3 million cost the state would incur to upgrade its computer.

Moyer said the state's database contains images of 25,000 shell casings but has produced only two matches, neither of which led to a crime being solved. With improved technology "on the horizon," Moyer said, the state should assess the program and allow other states to develop similar programs "before spending $2 million that we don't have."

During last fall's campaign, Ehrlich took the position that Maryland has enough gun laws and said he would consider repealing programs such as ballistic fingerprinting if they were ineffective. Yesterday's remarks fleshed out his philosophy, marking a clear departure from that of his predecessor, Parris N. Glendening (D), who pushed the database and other gun-control measures through the General Assembly.

Glendening's state police superintendent, David B. Mitchell, appeared at yesterday's hearing to testify in favor of the bill. Outside in the hall, he saw Moyer. "There's nothing to study here," Mitchell told Moyer. "We know this works." He and other proponents attributed the shift in position entirely to Ehrlich.

"He put the pressure on the state police, and he's hiding behind that $2 million one-time cost to not give law enforcement the tools they need and want," said Khalid R. Pitts, director of state legislation for the Coalition to Stop Gun Violence, a national gun-control group.

Sonia Wills, mother of one of last fall's sniper victims, testified yesterday in support of all three measures. Though none alone would have prevented the killing of her son, Montgomery County bus driver Conrad Johnson, she said they might prevent others from suffering as she has.

"I, along with millions of Marylanders, am morally outraged that we even have to debate the fact that sensible regulation of deadly firearms is a good idea," she said. "Had a national ballistic-fingerprinting system been in place, my son's life might have been spared. But since Congress refuses to act, we in Maryland must."

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives has said ballistics programs can provide valuable leads for investigators; opponents point to a California report last month that questioned the technology.

Jeffrey K. Reh, general counsel for Beretta USA Corp., said the technology costs his company's customers an extra $7 a gun in addition to the burden on taxpayers.

Beretta has 400 employees at headquarters in Prince George's. Senate President Thomas V. Mike Miller Jr. (D-Prince George's), whose district includes the plant, said the data suggest "the program has not been overwhelmingly effective."

Sonia Wills, mother of a sniper victim, testified for gun-control legislation.