Highland Park, July 4th parade shooting in Illinois

Monday’s shooting in Highland Park, Illinois, has brought renewed attention to a gun safety bill that was passed in Congress on June 24 and was signed into law by President Biden.

The bill marked a significant bipartisan breakthrough on one of the most contentious policy issues in Washington. “God willing, it’s going to save a lot of lives,” Biden said at the White House as he finished signing the bill on June 25.

In a statement following the Highland Park mass shooting, Biden noted that he had “surged federal law enforcement to assist in the search for the shooter,” and pointed to the gun safety legislation. “But there is much more work to do, and I’m not going to give up fighting the epidemic of gun violence,” Biden added.

The package represents the most significant new federal legislation to address gun violence since the expired 10-year assault weapons ban of 1994 — though it fails to ban any weapons and falls far short of what Biden and his party had advocated for, and polls show most Americans want to see.

The compromise legislation on gun safety was unveiled on June 21, and includes money for school safety, mental health, state crisis intervention programs and incentives for states to include juvenile records in the National Instant Criminal Background Check System, which would provide a more comprehensive background check for those between the ages of 18 and 21 who want to buy guns.

The legislation was finalized after days of haggling by lawmakers over several sticking points that had raised questions over whether the negotiations would fall apart.

Here’s what’s in the bill:

$750 million to help states implement and run crisis intervention programs: This money can be used to implement and manage red flag programs, which are aimed at keeping guns out of the hands of those who pose a threat to themselves or others. It also can be used for other crisis intervention programs like mental health courts, drug courts and veteran courts.

Whether the money could be used for things other than red flag laws was a primary sticking point at the end of the negotiations, and Republicans were able to secure money for states that don’t have red flag laws but have other crisis intervention programs.

Closing the so-called boyfriend loophole: This legislation closes a years-old loophole in domestic violence law that barred individuals who had been convicted of domestic violence crimes against spouses, or partners with whom they shared children or cohabitated with, from having guns. Old statutes didn’t include intimate partners who may not live together, be married or share children. The new bill would bar anyone who is convicted of a domestic violence crime against someone they have a “continuing serious relationship of a romantic or intimate nature” with from having a gun. The provision isn’t retroactive.

The bill, however, would allow those convicted of misdemeanor domestic violence crimes to restore their gun rights after five years if they haven’t committed other crimes.

Requires more gun sellers to register as Federally Licenses Firearm Dealers: The bill goes after individuals who sell guns as primary sources of income but have previously evaded registering as Federally Licensed Firearm Dealers. This is significant because federally licensed dealers are required to administer background checks before they sell a gun to someone.

More thorough reviews of people 18-21 who want to buy guns: The bill encourages states to include juvenile records in the National Instant Criminal Background Check system with grants, as well as implement a new protocol for checking those records. It gives NICS three days to review an individual’s record. If something potentially disqualifying comes up, NICS gets an additional seven days. If the review is not completed by then, the gun transfer goes through.

Read more about the bill here.

CNN’s Donald Judd contributed reporting to this post