In the final, blood-soaked weekend of 2018, 18 people were shot in Philadelphia. Three died, bringing the city’s death tally to 351, the highest since 2007. The new year brought more of the same; 11 minutes into 2019, a man was shot to death in Kensington.

In 84 percent of the city’s homicides, the weapon of choice was a gun.

This violence screams for a far more aggressive strategy to curb the flow of guns in the city. But little is known about the sources of the guns used in violent crimes, many of which are obtained illegally. More information about how these guns get into shooters' hands would help lawmakers pass legislation to make it harder for criminals to get these deadly weapons.

Philadelphia should take a page from Chicago’s playbook. For several years, Chicago has opened its crime gun trace data to the public. Working with the University of Chicago, police have analyzed the data and learned that 95 percent of crime guns in Chicago are traced back to someone other than the original purchaser, and that 91 percent of those guns wind up in the hands of felons. That evidence of a substantial illegal gun market helps Chicago educate the public and make the case to lawmakers and judges to crack down on repeat gun offenders. Also working with academics, Chicago has written an algorithm to help predict retaliation crimes.

Chicago’s death toll has gone down 18 percent from 653 in 2017 to 534 in 2018. While data analysis alone isn’t the only reason for the decline, it is an indicator of the city’s open-minded approach to solving its violence problem.

Philadelphia should adopt a similarly open approach to solving the gun crisis. This region has a wealth of universities and hospitals filled with creative minds. Harnessing that intellectual power could help us all.

Police already work with Temple University and others on crime issues, but imagine the possibilities of stepping up the game and fully sharing information with the experts and the public so they can understand more about what’s happening and come up with new solutions. Nothing stops police from disclosing where the guns come from and whether the shooters had permits for their guns.

District Attorney Larry Krasner is working to put charging, sentencing, and other information on the office’s website. The public disclosure should inspire a comprehensive analysis of how the office handles gun charges, whether judges drop them and why. Such an in-depth examination could help the office narrow its focus on what’s most effective.

Philadelphia needs a better understanding of gun violence to argue for passing its own gun laws, an idea State Rep. Dan Frankel (D., Allegheny) has put in a bill that deserves support from his Statehouse colleagues, especially those in this region.

Mayor Jim Kenney is expected to soon release a strategy to attack violence as the public-health crisis it is. The report should include a range of tactics, from better targeting of antipoverty and education programs to sharing information with the public and fostering a spirit of experimentation. The old strategies just aren’t effective enough.