In the annals of rank opportunism, Rep. Anna Eshoo, D-Calif., deserves a special place. All hail her efforts to exploit the Beltway-sniper killings by pushing a bad "ballistic fingerprinting" bill. Her measure -- oddly dubbed -- is the Ballistics, Law Assistance and Safety Technology Act, or BLAST Act. Devoid of shame, Eshoo argues that if her bill were in force, authorities could find the anonymous shooter. Does she really believe that? "Oh yes, absolutely," Eshoo said. "If we already had a national system in place and operating today, there would be a direct linkage between the spent casings" from the gun and the owner of the gun. Sure. There are millions of old firearms in America, yet a methodical sniper would choose a ballistics-signature-on-file gun to shoot strangers? I don't think so. What would it cost to have manufacturers and importers fire and store ammo from each new gun and pass the data on to a national database, as her bill mandates? Eshoo doesn't know. Does it make sense to create this new bureaucracy when there are already so many guns in America -- estimated at more than 200 million -- that don't have their ballistic images on file? I'll add that advocates say that most crimes are committed with stolen guns, which thus, could not be traced to the user. (A Bureau of Alcohol, Tobacco and Firearms spokesman said the ATF kept no numbers on stolen guns used in crimes, but a 1997 federal survey of state prison inmates found that 12 percent of those who possessed guns bought them in a retail store or pawn shop; 80 percent came from family, friends, a street buy or an illegal source.) Those questions deserve answers, which is why Rep. Melissa Hart, R-Pa., introduced a smart bill last December to study if ballistic fingerprinting would work and be a good use of law enforcement dollars. Initially skeptical, President Bush is now said to be exploring the issue. Gun advocates say "ballistic fingerprinting" is a misleading term because ballistic signatures are easily changed. Sam Paredes of the pro-gun Gun Owners of California said that firing a gun repeatedly can change the imprints. He added that with a fingernail file, an abrasive substance and a long stick, "It is easier to change the ballistic fingerprint of a firearm than it is to change the oil in your car." Eshoo dismissed such talk as "NRA propaganda." Wrong. A preliminary report by the California Bureau of Forensics on the feasibility of setting up a state database on new handgun sales found that the "number of candidate cases will be so large as to be impractical and will likely create logistic complications so great that they cannot be effectively addressed." Also, it is "unknown" if a casing fired "after a typical break-in and wear" would match a factory-fired first casing. And: The markings can be "readily altered by the user. They are not permanently defined identifiers like fingerprints and DNA." State Attorney General Bill Lockyer's spokesperson Hallye Jordon noted that the study is not complete. OK, but that didn't stop Lockyer from issuing a press release this week calling on the federal government to "make it a top national priority to complete the research, overcome any technological obstacles, and fully fund the creation and maintenance of a national database." Once again, the rush to make headlines trumps solid public policy. Eshoo said that she introduced the bill because "the only thing that we have on the ground now are the people who have been shot dead, and spent casings." Some improvement: dead bodies, spent casings, and an extra layer of feckless law enforcement.