Jitka Vesel was shot 12 times at close range with a gun her killer never should have owned.
On Friday, an online seller learned he will go to prison for illegally arming the man who pulled the trigger.
Benedict Ladera, 31, of Kent, Wash., received a one-year term for supplying the .40 caliber handgun used to murder Vesel last year in an Oak Brook parking lot.
Prosecutors said he sold the weapon to Dmitry Smirnov for an extra $200, knowing Smirnov was a citizen of Canada and not eligible for gun ownership.
"By purposefully violating the law, the defendant put this gun in the hands of a murderer," said U.S. Attorney Jenny Durkan of the Western District of Washington.
Smirnov ambushed Vesel, 36, of Westmont, on April 13, 2011, as she left a volunteer function at the Czechoslovak Heritage Museum on 22nd Street.
Less than four months later, he accepted a life sentence and gave a stunning in-court confession in which he blamed Vesel for "dumping" him years earlier.
Prosecutors said Smirnov, then 21, found his murder weapon at armslist.com and bought it from Ladera after arranging to meet outside a Washington casino.
Ladera didn't know of Smirnov's plan to kill, authorities said, but he was "so disturbed" by his customer that he refused to supply him with bullets.
U.S. District Judge Robert Lasnik said Ladera, at best, was reckless in selling a weapon over the Internet to a man he knew hardly anything about.
"Guns are killing people all over our country every day," Lasnik said, according to a news release. "We cannot afford to lose the people we are losing."
Vesel's longtime friend, Theresa O'Rourke of Downers Grove, seized Friday's sentencing as an opportunity to push for stricter gun laws.
She cited statistics from the U.S. Department of Justice and the Mayors Against Illegal Guns organization that indicate 40 percent of firearms are sold by "private sellers" not required to do background checks.
O'Rourke said she believes this is a result of unchecked online sales, which have grown in popularity.
"Nobody wants to take away people's guns," she said. "I'm just saying, if you want to own a gun, you need to go through a background check."
"I have a constitutional right to vote," she added, "but I still have to register."
O'Rourke said she is calling attention to the cause through news conferences and letter-writing campaigns.
"I think we've planted seeds to help educate people," she said.
Vesel met Smirnov, formerly of Russia, while playing an online video game, and the two developed a kinship because they each were immigrants, O'Rourke said.
She said they met and dated briefly in 2008 but Smirnov continued to contact Vesel against her wishes after the relationship ended.
Prosecutors said Smirnov acquired ammunition from a transient before traveling to Illinois and putting a tracking device on Vesel's car, eventually locating her at the museum.
Of the 12 shots he fired, two struck Vesel in the back and five in the head.
O'Rourke described Vesel as "genuine" and an honest person who worked as a Czech translator and spent her free time volunteering and helping her elderly neighbors.
"I was blessed to know such a wonderful person but, at the same time, it's so incredibly hard to not have that incredible person in my life anymore," she said.
O'Rourke said she was satisfied with Ladera's sentence but saddened because Vesel shouldn't have been killed.
"Her murder was preventable, and she was failed. The American system and the American dream failed her by allowing her stalker, her murderer, to obtain a gun without a background check, without a single question asked," O'Rourke said. "She didn't deserve to die alone in a parking lot with no one there, with no one to hold her hand, with no one to comfort her. Her life wasn't finished."
Ladera pleaded guilty in March to illegal transfer of a firearm to a nonstate resident. In addition to prison time, he must serve three years of supervised release, federal officials said.