Standing in front of phalanx of more than a dozen Massachusetts police chiefs, gun-control activist John Rosenthal called out the state Senate this morning for giving in to pressure from the gun lobby in weakening new gun legislation making its way through the State House.

The Senate last week amended a gun control bill passed by the House by stripping out a provision that would give local police chiefs the authority to determine a resident’s suitability to obtain a firearms ID card for a rifle or shotgun. Police chiefs currently have the power to approve or deny licenses to carry a handgun. Law enforcement officials who gathered this morning at the State House said extending that same discretion to “long guns” would represent an important step in strengthening the state’s gun laws, which are already among the most stringent in the country.

Boston Police Commissioner William Evans: “I’m real disappointed in the Senate.”

“What the Senate chose to do was placate the NRA instead of responding to law enforcement,” said Rosenthal, a developer who owns the iconic anti-gun violence billboard that looms over the Massachusetts Turnpike near Fenway Park.

Terry Cunningham, the Wellesley police chief, cited a scenario in which police are called repeatedly to an address for a domestic disturbance between a couple living there. Cunningham said he could deny an application from the man living there for a license to carry a handgun, but would be unable, under current law, to deny him a firearms ID card for a rifle based on the perception that he lacks self-control or has propensity to be violent. “I find it completely illogical. I find it mortally offensive that I have to issue a license,” he said. “Are people really going to be any less dead if they’re killed with a rifle or shotgun than a handgun?”

Also speaking out against the Senate bill at the event were Boston Police Commissioner William Evans and the city’s former commissioner, Ed Davis.

“I’m real disappointed in the Senate,” said Evans. “We try our best but we need the legislators’ help in helping us control violence.”

Gun rights advocates say police chiefs have abused the discretion they already have over handgun licenses.

Sen. James Timilty, the Senate chairman of the Legislature’s Joint Committee on Public Safety and Homeland Security, has also raised concerns that the licensing provision for rifles and shotguns could violate the US Constitution’s Second Amendment.

The 28-11 vote in the Senate to strip out the police chief discretion provision had the surprising support of several of liberal stalwarts, including Majority Leader Stan Rosenberg, who is in line to become Senate president next year. Rosenberg, an Amherst Democrat, was not available to comment on Tuesday, his office said.

The Greenfield Recorder quoted him over the weekend defending the vote to maintain the status quo. “We’re just saying that for long guns, we’re sticking with the current procedure because there’s adequate oversight and control through the federal government,” Rosenberg said.

Warren Tolman and Maura Healey, who are facing off in the Democratic primary for attorney general, both attended the event and voiced support afterwards for the new discretionary authority given to police chiefs in the House bill. Healey deflected a question asking whether she has spoken about the issue with Rosenberg, who has endorsed her.

A legislative conference committee will try to work out differences between the two bills before the end of the session on July 31.