Pennsylvania Governor Tom Corbett signed the already two-months-old 'Brad Fox Law,' a crackdown on gun straw purchasers.
The law includes mandatory 5-year prison terms for those caught a second time.
Straw purchasers are people with no rap sheet who are able and willing to buy guns for convicted felons, who are barred from making that transaction.
It's called the Brad Fox Law because of the classic nature of the Plymouth Township officer's murder back in September. Fox, a decorated Marine Corps veteran, was ambushed by Andrew Thomas, a career criminal who allegedly got the weapon from Michael Henry.
The law that existed when Fox was killed was widely judged to be too lenient. The governor officially signed the new law back in late October.
"Officer Fox died in the line of duty last year at the hands of a felon who should never have had a gun and, less directly, by the hand of the man who later admitted buying the gun and passing it along,'' said Corbett.
"Such 'straw buyers' are as deadly a threat to our citizens and our first responders as the felons to whom they pass along the weapon," he added.
"It will give us the tools to convince straw purchasers to give us information about those criminals who have guns on the street," said Montgomery County District Attorney Risa Ferman.
"We should listen to the people and give them what they want, which is efforts to fight gun violence in Pennsylvania," said gun control advocate Shira Goodman.
The Harmonville Fire Company firehouse in Plymouth Meeting was packed with Fox's fellow officers from Plymouth and other regional agencies.
Officer Fox's trusty K-9, Nick, who was also wounded that fateful day, was there, too, sitting with Officer Fox's family. They are still coping with his untimely death. His widow is expecting their second child in March.
"It's just an honor to be able to be part of this and know that Brad's legacy will always carry on, and even after four months we still have the support of the community, and it will continue," said Fox's widow, Lynsay.
"He's still making changes even though he's not here with us now, he's still affecting people's lives. I'd expect nothing less out of him," said Fox's brother, Jim.
