Bellis argues in her decision there was no "negligent entrustment of a firearm".
Families of some of the children and staff killed on December 14, 2012, brought the suit to hold Remington liable for the attack - with the main argument being the.223 mm semiautomatic assault rifle is manufactured to kill people.
Judge Barbara Bellis ruled that the suit against the Remington Outdoor Co., the manufacturer of the AR-15 assault rifle used in the massacre, is not permitted by federal law.
"The gun lobby is the most powerful lobby in Washington", she said.
The families had attempted to sue Remington for promoting the military-style gun to civilians after Adam Lanza used it kill 20 children and six staff at Sandy Hook Elementary School.
But the families' attorneys argued the lawsuit was allowed under an exception in the federal law that allows litigation against companies that know, or should know, that their weapons are likely to be used in a way that risks injury to others.
In their motion to strike the case, the defendants argued that they are granted immunity from this sort of wrongful death claim by the Protection of Lawful Commerce in Arms Act - a law passed by Congress in 2005 that was created to protect gun makers from this kind of civil liability lawsuit.
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The families" attorney, Josh Koskoff, told the Courant that they would appeal the ruling, and that they "deserve' to have their case heard.
Remington could not be reached for immediate comment. Gun control has become one of the key points of presidential candidate Hillary Clinton, who criticized her former rival Bernie Sanders for his support of the law back in 2005. "As I have stated before, the laws providing unique protections to gun manufacturers need to be changed to give crime victims a right to pursue legal remedies".
Bellis, in a 54-page memorandum of decision, wrote that the arguments presented by the families "did not satisfy the negligent entrustment exception" to the federal shield law.
"While the families are obviously disappointed with the judge's decision, this is not the end of the fight".
The judge ultimately dismissed their lawsuit because of the gun industry's protections under PLCAA, as well as a Colorado immunity law.
An attorney for the families said that this was not the final stage for the case, saying that they planned to appeal in court. The lawyers for Remington recently filed a request for the judge to issue an order preventing the company from turning over as part of the discovery process anything the company believes are trade secrets or anything that could later be used to compromise its business. Lanza, 20, killed himself as police approached.
