A federal judge blocked the key section of Connecticut's new convertible pistol law one day before it was scheduled to take effect.

U.S. District Judge Kari A. Dooley issued the preliminary injunction Wednesday, Sept. 30. The ban had been set to go into force Oct. 1. Glock, the firearms manufacturer, had sued the state to stop the law, known as House Bill 5043. In a 12-page ruling, Dooley found the ban is "likely unconstitutional under the Second Amendment to the United States Constitution," as WTNH first reported.

WTNH had reported Sept. 25 that the convertible pistol ban was among more than 90 new Connecticut laws set to take effect Oct. 1.

Gov. Ned Lamont signed HB 5043 in June. The law outlaws the future sale, manufacturing, purchase and importation of convertible pistols in Connecticut, though it applies only to handguns manufactured after Oct. 1. Previously owned Glocks are unaffected, according to the Hartford Courant.

Lawmakers who backed the bill said it targeted design features in Glock handguns that make them easy to convert from semiautomatic to automatic fire using illegal devices called "Glock switches." Converting a semiautomatic weapon to automatic and possessing Glock switches were already illegal under existing law.

The bill passed the state House 86-64, with 15 moderate Democrats joining all Republicans in opposition. It passed the state Senate 22-11, along mostly party lines.

Dooley applied a two-step Second Amendment framework from a 2022 U.S. Supreme Court decision. Because the state accepted that HB 5043 implicates the Second Amendment's plain text, the statute was presumptively unconstitutional. The state then had to prove the law fits within the historical tradition of firearms regulation.

The state pointed to the decades-old ban on machine guns as precedent. Dooley sided with Glock's argument that the historical trend has been to target the act of converting a legal weapon into an illegal one, not to ban the underlying firearm.

"For example, when confronted with the dangerousness of a 'sawed-off shotgun' the response was to ban the modified shotgun, not to ban shotguns altogether," Dooley wrote.

The law also drew criticism from police departments. Glock handguns are widely used by law enforcement agencies across Connecticut, and the law contained no exemption for police. Seymour Police Chief John Bucciariati told Fox 61 the missing exemption could affect departments that need to replace their service weapons.

Attorney General William Tong said in a statement that Connecticut does not agree with the court and will continue to defend the law. Senate Democratic leaders Martin Looney and Bob Duff said in a joint statement they would keep fighting in court to protect communities and police officers.

State Sen. Rob Sampson, a Republican, called the law poorly conceived and said it unfairly targeted legal firearms based on what a criminal might illegally do with them.

The preliminary injunction keeps the ban on hold while the case moves forward. No date for the next court hearing has been announced.