''The mere fact that defendants' conduct in their plants, offices, and stores puts guns into the stream of commerce does not state a claim for public nuisance," the court said. ''It is the presence and use of the guns within the city of Chicago that constitutes the alleged nuisance."
The city sought $433 million, the amount it estimated it paid in law enforcement and emergency medical treatment for gun violence over four years. The families sought unspecified damages.
Similar lawsuits had been filed around the country. An earlier wave of product liability lawsuits alleging that guns are unreasonably dangerous failed.
The city of Boston filed a $100 million lawsuit against 31 gun manufacturers in 1999, the first case in the nation to aggressively press the gun industry on illegal sales and the failure to manufacture safer weapons. But in 2002, the city dropped the case due to budget difficulties.
Seth Gitell, spokesman for Boston Mayor Thomas M. Menino, said the Chicago case fits a pattern regarding civil cases of its kind, with the gun manufacturers prevailing over municipalities. ''That lawsuit was definitely a move in a positive direction, but what we saw with the Chicago case, that fits a broader general action with these cases," he said.
Chicago's lawsuit cited an undercover operation in which officers bought guns at suburban shops even after telling the sellers that they were gang members, buying them for gang members, or taking them to Chicago, where handguns are banned.
''Allegations about defendants' conduct, if true, suggest that defendants were not only aware that their products were used by third parties for criminal acts, but the defendants affirmatively sought to increase their profit by pandering to that market," the five justices said in their concurring, separate opinion.
Chicago Mayor Richard Daley called the ruling disheartening. ''More drug dealers and gang-bangers are buying more guns," he said. ''It has nothing to do with the Constitution, and it has nothing to do with hunters and sportsmen and collectors. It's a safety issue."
The manufacturers sued included Smith & Wesson and Sturm, Ruger & Co.
Globe corresepondent Heather Allen contributed to this report.
