The data shows that roughly one-third of the 155,000 firearms traced by U.S. officials that year came from sources located outside of the states in which they were found.
In Connecticut, officials traced a total of 624 guns, of which 275 (44.1 percent) were purchased in other states -- most notably New York (14.5 percent), North Carolina (10.5 percent), and Florida (7.6 percent).
Officials also traced 593 guns to Connecticut, of which 244 (41.1 percent) were recovered out-of-state, in places such as New York (16.8 percent), Florida (11.1 percent), and California (seven percent).
Speaking on WNPR's Where We Live, ProPublica reporter Eric Sagara said it's important to keep in mind that not all of the recovered firearms were taken out of circulation. He also noted that the data collected does not necessarily represent all of the guns that were recovered by law enforcement in 2012.
"Not all states or not all agencies run traces on every single gun that they come across," Sagara said. "So, this number that we have published here is actually probably going to be fairly light -- by thousands nationwide."
Listen to the full interview below: