Surrounded by the families of Sandy Hook’s victims, Gov. Dannel Malloy signed one of the nation’s most comprehensive gun control packages into law at noon on Thursday.

The signing took place just 10 hours after the bill passed through the legislature early Thursday morning with strong bipartisan support. The new law — a long-awaited legislative response to the massacre that befell Newtown on Dec. 14 — tightens gun restrictions and contains provisions to strengthen the state’s mental healthcare system and school security apparatus. The bill’s passage also became a national symbol of unusual bipartisan cooperation on a bitterly partisan issue, a feat that the federal government has not yet been able to achieve.

“This is a profoundly emotional day, I think, for everyone in this room,” Malloy said. “We have come together in a way that relatively few places in our nation have demonstrated an ability to do.”

Immediately upon Malloy’s signature, the sale of over 100 types of assault-style weapons and magazines holding more than 10 bullets became illegal in Connecticut. Anyone seeking to purchase a gun must now undergo a universal background check as well.

Other controvertial provisions of the law will take effect later in the year. On July 1, Connecticut residents will be required to possess a permit in order to buy long rifles and ammunition. A gun offender registry, which will be accessible solely to law enforcement officials, will be established by October 1. To the disappointment of many gun-control advocates, the final deal also contains a “grandfather” clause that will allow current gun owners to keep newly banned weapons and magazines as long as they are registered.

Before the governor signed the bill into law, Nicole Hockley, who lost her son Dylan during the Sandy Hook shooting, stood to commemorate the moment.

“While I am greatful for the progress being made, I wish more than anything that I could just be home, waiting for Dylan and Jesse to both come home,” Hockley said.

Hockley said that before Sandy Hook, she never felt engaged in politics. She has since met the president and worked with Connecticut’s two senators to advocate for new gun control measures; next week, she will travel to Washington to make her appeal on a national scale.

Hockley is not alone. Thursday’s audience was studded with gun control advocates, many of whom only became advocates after the shooting in December.

But the new law has already gained significant opposition as well. In anticipation of Thursday’s signing, customers packed gun shops across the state to stock up on weapons that were soon to be banned. The National Shooting Sports Foundation threatened to bring a legal challenge to the law in a statement released after the signing.

Many of the Republicans who voted for the bill have been ensnared by the ire of the gun lobby. Senate Minority Leader John McKinney ’86 and House Minority Leader Lawrence Cafero — both architects of the bipartisan compromise — found themselves targets of attack from gun rights groups throughout the deal-making process. Cafero did not attend the bill signing ceremony, and McKinney arrived near the end, citing personal matters.

As of Thursday, Malloy has signed four bills into law so far this legislative session.