A Craigslist-like website that facilitates weapons sales between buyers and sellers cannot be liable for the actions of its users, including the murder of a woman by a handgun advertised on the site, a federal appeals court ruled.

The case decided Tuesday by the 7th US Circuit Court of Appeals concerns a woman murdered in 2011 with a .40-caliber handgun that a Seattle man advertised on Armslist for $400. A Canadian man bought the weapon.

Demetry Smirnov, the gun purchaser, murdered Jitka Vesel in Chicago with that weapon after an online romance soured. He pleaded guilty and was sentenced to life in prison. The man who sold him the gun, Benedict Ladera, was handed a year in jail for illegally selling the firearm, as federal regulations prohibit the transfer of weapons to people in another state or country, the appeals court said.

The slain woman's brother, Alex, sued the website for damages, among other things, alleging negligence.

A three-judge panel of the Chicago-based federal appeals court tossed the suit:

Alex has alleged nothing of the sort here. Alex’s complaint states that Armslist "design[ed] its website to encourage its users to circumvent existing gun laws… by easily enabling prospective purchasers to search for and find gun sellers in any and all states." But simply enabling consumers to use a legal service is far removed from encouraging them to commit an illegal act.

The court added: "Armslist permitted Ladera to place an advertisement on its website and nothing more. It did not invite Ladera or Smirnov to break the law. Alex’s allegations fall short of alleging any cognizable negligence claim for which Armslist could be held responsible for Smirnov’s acts."

The website's lawyer, James Vogts, told The Wall Street Journal that the woman's death was a "tragedy," but the lawsuit "had no merit and should never have been filed."