Hartford — The Connecticut gun shop that sold Nancy Lanza the Bushmaster rifle used in the Sandy Hook Elementary School massacre filed for bankruptcy this week but a lawsuit filed by family members of some victims will go forward, a judge ruled Thursday.

Superior Court Judge Barbara Bellis ruled the case against the gun shop, Riverview Sales Inc. in East Windsor, will be delayed until the bankruptcy proceedings are complete.

In a 32-page filing, Riverview Sales President David LaGuercia said his business owes about $140,900 to creditors and has about $825 in assets that includes 100 boxes of unspecified ammunition, 10 boxes of shotgun shells, shooting target sand and a couple of rifle scopes.

The gun shop lost its federal firearms license on Dec. 20, 2012, eight days after Adam Lanza killed 26 people, including 20 first-graders, at the Newtown school using a Bushmaster AR-15 that his mother had legally purchased at Riverview in 2010. Lanza then killed himself using a Sig Sauer pistol his mother also bought at Riverview in 2011.

During a 2012 raid, federal agents discovered approximately 300 examples of false or missing information in Riverview’s acquisition and disposition records. The investigation also revealed at least two instances in which individuals received firearms prior to receiving approval from the national instant criminal background check system.

Riverview also failed to report the theft of a firearm within 48 hours, and failed to report multiple sales of handguns to the same individuals.

LaGuercia pleaded guilty in federal court to two misdemeanor charges — transfer of a firearm before the completion of background check and failure to maintain proper firearm records — and received a suspended sentence.

The gun shop had stayed open after the gun permit was pulled, selling ammunition and other gun accessories, but business declined quickly and steeply.

The largest creditor of Riverview is a company called Our Nation’s Best Sports Corp., based in Fort Worth, Texas, which is owed $101,917, records show.

Riverview also owes $5,000 to Camfour Inc., a Massachusetts-based gun distributor that is also a defendant in the lawsuit currently pending in Bridgeport Superior Court. The bankruptcy filing also lists all 26 families or estates of those killed at Sandy Hook as potential creditors.

Ten of the victims’ families, plus school administrator Natalie Hammond who was shot and survived, have sued Remington Arms, the manufacturer of the Bushmaster, Camfour and Riverview arguing that the companies negligently marketed a gun they knew was designed only for military use to the public to boost gun sales.

Riverview also owes $7,500 to Bloomfield attorney Peter Barry, who is representing it in the gun lawsuit, records show. Barry filed a motion late Wednesday informing the judge of the bankruptcy and seeking a stay in that case until the bankruptcy is completed.

Bellis held a hearing in the case Thursday and urged the parties to meet in private to iron out a confidentiality agreement related to company documents that the plaintiffs have sought through the discovery process.

Bellis has allowed discovery to proceed even as she weighs a motion by Remington Arms to dismiss the lawsuit because the gun companies are immune to lawsuits under a federal law known as the Protection of Lawful Commerce in Arms Act, or PLCAA.

Remington, the principal defendant, has asked Bellis to keep records it views as proprietary from being made public for competitive reasons.

“There is going to be some protections that are going to be put in place here, I don’t think there is any question about that,” Bellis said Thursday.

She said she will rule on the confidentiality of any documents about which the parties can’t agree.

Remington’s attorney, James Vogt, said the company has not yet turned over any documents it believes should be confidential.

The records that Remington wants to keep confidential include market research, including branding and promotions, consumer satisfaction and demographics, promotional and sales strategies, the number of firearms manufactured or sold by specific model and names, and addresses or other personal identifying information of firearm purchasers.

Attorneys for the families that are suing the gunmaker called the request “repugnant.”

“Remington did not become the country’s leading seller of military weaponry to civilians by accident. It ascended to that position through its calculated marketing and pursuit of profit above all else,” attorney Josh Koskoff wrote in a filing. “Plaintiffs lost family members, including children, in the service of that bottom line. Now Remington wants them to do more to protect its profitability. Plaintiffs will of course abide by whatever order the Court enters, but they will not by agreement help in a cover up of Remington’s marketing strategies or profit margins.”