A St. Paul man has admitted that he illegally sold large quantities of weapons online while posing as a gun collector in one of the first cases charged in the wake of President Obama’s pledge to crack down on unregulated firearms sales.

Eitan B. Feldman, 29, pleaded guilty Friday in U.S. District Court in Minneapolis to dealing in firearms without a license. Feldman remains free on $25,000 unsecured bond as he waits sentencing on a date to be determined. Feldman’s was the third unlicensed-seller case charged by the U.S. attorney’s office in the past decade.

Several of the handguns sold from January 2014 to January of this year soon turned up at Twin Cities crime scenes, according to federal authorities. Of the 41 guns Feldman bought and resold during this period, the average time he actually possessed a gun before offering it for resale was nine days. Authorities said his average profit on each sale was $90.

In July 2015, an agent with the federal Bureau of Alcohol, Tobacco and Firearms (ATF) told Feldman that some of the firearms he had bought and then transferred for pickup at L.E. Gun Sales in Burnsville had been linked to crime scenes days later after he sold them.

A few months later, ATF agents warned Feldman in writing that continuous sales of guns made him an unlicensed “dealer in firearms” and that he should stop immediately or risk prosecution. But Feldman made at least eight more sales, including two to undercover federal agents. Those agents were not asked for identification or screened to determine whether they were barred legally from buying firearms.

According to the indictment, Feldman advertised on a website called Armslist.com to sell more than 40 guns he had earlier bought from licensed dealers online.

Feldman first had the firearms transferred to L.E. Gun Sales, where he would receive them after completing required paperwork and submitting to a background check.

The ATF found evidence linking him to several handguns used in violent crimes and drug trafficking:

• A Ruger .380 pistol allegedly bought from Feldman was used in Minneapolis just one week after he obtained the weapon. Minneapolis police found shell casings from the pistol at the scene of a March 2015 shots-fired call, and they were later linked to an April assault, according to court documents.

• Bloomington police investigating the transport of 50 pounds of marijuana to Minnesota also found a Taurus .38-caliber revolver that one suspect allegedly bought from Feldman.