The Massachusetts Governor is again appealing to lawmakers to approve his sweeping gun control bill.
Patrick is testifying before a hearing of the Public Safety Committee at the Statehouse on Friday.
The committee has been holding hearings on nearly 60 gun-related bills across the state this summer.
Patrick's legislation would tighten access to high-powered rounds of ammunition, create four new types of firearms-related crimes and mandate that buyers undergo background checks before purchasing weapons at gun shows.
Critics say the bill goes too far and would punish law-abiding gun owners, and gun rights advocates plan to speak out.
Before the 10 a.m. hearing, supporters of tougher gun measures plan a press conference in front of the Massachusetts House chambers. They include parents of children killed at Sandy Hook Elementary School in Newtown