Just under half of all the guns Boston police confiscated after they were used for crime last year came from outside Massachusetts, the department said.
Of 667 guns analyzed for their origins, 333 of them were from out of state, and 138 from the Bay State. As for the rest, their origin is unknown, said Sergeant John Boyle, a department spokesman.
The breakdown gives a glimpse as to the course weapons travel before they are used in violent crimes on the city’s streets.
Statistics for guns the department traced for this year are not yet available.
Boston police Sergeant Detective Catherine Doherty, who works in the department’s forensic firearms analysis unit, said that the state’s strict gun laws and the paucity of gun shops in Greater Boston prompts some to look outside of Massachusetts for firearms.
“We have the best gun laws and we have one of the lowest crime rates in the United States as a result directly of those laws,” she said.
Massachusetts had the lowest gun death rate in the country in 2016, according to Centers for Disease Control data, and the state’s gun safety laws are considered to be stringent by US standards. States like New Hampshire and Maine are considered to have looser gun laws.
The licensing process for guns in Massachusetts gives police chiefs wide discretion to approve or reject applications. Chiefs can deny licenses to people deemed to be a threat. Applicants must also clear a state background check. Gun dealers are also licensed in Massachusetts, and they must conduct a background check for every sale.
Additionally, private sellers in Massachusetts must validate a buyer’s license and report the transfer to the state. The state also has a ban on the sale and possession of assault weapons and high-capacity magazines.
Doherty, whose unit handles about 1,200 cases involving guns or ammunition each year, said if other states followed Massachusetts’ lead in passing strong gun laws, the effect would be seen on the city’s streets.
“If all the laws were comparable throughout the states, we’d have a much lower crime rate,” she said during an interview at police headquarters.
Police trace a gun’s origin with help from the federal Bureau of Alcohol, Tobacco, Firearms, and Explosives, Doherty said. Information about the gun dealer and the first buyer is obtained, she said.
Investigators are always curious about the connection between the lawful purchase of the gun and the crime, she said.
“That’s a very important thing that we want to know about,” she said.
The department’s forensic firearms analysis unit has so far received 301 guns this year, a mix of weapons seized by police and those turned in to the department, according to police. At this time last year, the unit had received 259 guns, Boyle said.
She said between 5 and 10 percent of the guns her unit receives are reported stolen. That number, however, could be higher and may be skewed, said Boyle, as many people don’t report their firearm stolen.
Asked what areas of the city have the highest concentration of illegal guns, Doherty named north Dorchester and pockets of Roxbury and Mattapan.
“That’s something that’s pretty common knowledge,” she said.
The total number of shootings in the city was found to have decreased from last year, according to recent statistics. Citywide, the total number of shootings between Jan. 1 and June 10 decreased from 90 last year to 76 this year, although fatal shootings saw an uptick from 12 to 19.Previous Globe coverage was used in this report. Danny McDonald can be reached at firstname.lastname@example.org. Follow him on Twitter @Danny__McDonald.