Angered by her announcement last week that her office will step up its enforcement of the state's assault weapons ban, a bipartisan group of 58 lawmakers sent Attorney General Maura Healey a letter over the weekend opposing "in the strongest possible terms" her decision and the way she announced it.

Healey last week announced that she will crack down on enforcement of the state's 1998 assault weapons ban, specifically focusing on what she called "copycat" versions or duplicates of firearms banned under that law.

A gun qualifies as a forbidden copycat if it is "substantially similar in construction and configuration" to one of the banned guns or has interchangeable key parts, according to the enforcement notice.

"For the last 18 years, the law has been implemented and enforced consistently, both by your office and your predecessors," the legislators wrote. "Your new directive, which has been presented by your office as nothing more than a closing of 'loopholes' in the current law, appears in fact to be much more than that: the enforcement of a whole new law that unfairly infringes on the Second Amendment rights of law-abiding gun owners in Massachusetts."