The National Integrated Ballistics Information Network (NIBIN), a database of ballistic evidence from crime scenes, seeks to provide investigative leads by linking separate offenses involving the same weapons. Using surveys about 570 gun crimes in Indianapolis, Kansas City, and Phoenix, we examine perceptions of NIBIN, and whether lead timeliness influences those perceptions. Detectives who receive NIBIN leads sooner after a crime occurs have significantly higher odds of reporting the lead as helpful. The predicted probability of a lead being perceived as helpful is 43.11% if received 30 days after a crime, but only 17.80% 1 year later. Leads were more helpful for robberies and homicides than other offenses. To maximize the utility of NIBIN, agencies should prioritize rapid evidence processing.