The new billboard is a product of the group Stop Handgun Violence, the same Boston-based advocacy group that long spread its message from a highly visible site near Fenway Park and the Massachusetts Turnpike.

Top-ranking state and local law enforcement officials attended an unveiling for the 90-foot banner, which is mounted on a Back Bay garage. The sign reads: “We’re not anti-gun…We’re for life: Massachusetts Gun Laws Save Lives.”

To commemorate the three-year anniversary of the Newtown, Conn., elementary school shooting that left 26 people dead, a Boston advocacy group on Monday unveiled its latest billboard encouraging stricter federal gun laws.


John Rosenthal, founder of Stop Handgun Violence, said in a statement that he hopes to use Massachusetts as an example for how the federal government could get a better handle on gun deaths.

“Stop Handgun Violence is not trying to ban guns other than military style assault weapons and large capacity ammunition magazines — the common denominators in the daily mass shootings,” he said. “What we are trying to do is save lives.”

Since the Sandy Hook shooting, there have been 161 other school shootings in the country, and more than 96,000 more people have been killed from gun violence, the organization said.

The group has posted its latest billboard on a parking garage at 50 Dalton St., and plans later to install a permanent billboard on Rosenthal’s Fenway Center development when it’s constructed in Kenmore Square.

In a statement Monday, Suffolk District Attorney Daniel F. Conley said he is a “staunch supporter” of Rosenthal and his message.

“But the fact is that we’re just treading water until the nation’s lawmakers tackle this life-and-death issue. Gun laws work,” Conley said. “We’ve proven it here in Massachusetts, and we have to bring that message to Washington. John Rosenthal and Stop Handgun Violence are doing just that.”


The prosecutor was joined by Mayor Martin J. Walsh, Police Commissioner William Evans, and Attorney General Maura Healey to unveil the billboard, according to Stop Handgun Violence.

Conley said he thinks the group is correct to highlight the experience of Massachusetts in attempting to limit handgun deaths.

In a 2013 study in the Journal of the American Medical Association, Massachusetts was at the top of the list for legislative strength and the bottom of the list for overall gun deaths, Conley’s office said.

Walsh said in a statement that the nation must work together to tackle “the gun issue” in a way that will keeps neighborhoods safe.

“In Boston this past year, we’ve taken hundreds of guns off the street and we’ve reached out to gun owners about how to keep their weapons safe and out of the hands of criminals,” he said. “It is important that we continue working together to overcome what might seem like insurmountable barriers to sensible gun control, and show the nation a way forward.”

Felicia Gans can be reached at felicia.gans@globe.com. Follow her on Twitter @FeliciaGans.