Police in Philadelphia, Pennsylvania, routinely transport patients with penetrating trauma to nearby trauma centers. During the past decade, this practice has gained increased acceptance, but outcomes resulting from police transport of these patients have not been recently evaluated. To assess mortality among patients with penetrating trauma who are transported to trauma centers by police vs by emergency medical services (EMS). This cohort study used the Pennsylvania Trauma Outcomes Study registry and included 3313 adult patients with penetrating trauma from January 1, 2014, to December 31, 2018. Outcomes were compared between patients transported by police (n = 1970) and patients transported by EMS (n = 1343) to adult level I and II trauma centers in Philadelphia. Police vs EMS transport. The primary end point was 24-hour mortality. Secondary end points included death at multiple other time points. After whole-cohort regression analysis, coarsened exact matching was used to control for confounding differences between groups. Matching criteria included patient age, injury mechanism and location, Injury Severity Score (ISS), presenting systolic blood pressure, and Glasgow Coma Scale score. Subgroup analysis was performed among patients with low, moderate, or high ISS. Of the 3313 patients (median age, 29 years interquartile range, 23-40 years) in the study, 3013 (90.9%) were men. During the course of the study, the number of police transports increased significantly (from 328 patients in 2014 to 489 patients in 2018; P = .04), while EMS transport remained unchanged (from 246 patients in 2014 to 281 patients in 2018; P = .44). On unadjusted analysis, compared with patients transported by EMS, patients transported by police were younger (median age, 27 years interquartile range, 22-36 years vs 32 years interquartile range, 24-46 years), more often injured by a firearm (1741 of 1970 88.4% vs 681 of 1343 50.7%), and had a higher median ISS (14 interquartile range, 9-26 vs 10 interquartile range, 5-17). Patients transported by police had higher mortality at 24 hours than those transported by EMS (560 of 1970 28.4% vs 246 of 1343 18.3%; odds ratio, 1.86; 95% CI, 1.57-2.21; P < .001) and at all other time points. After coarsened exact matching (870 patients in each transport cohort), there was no difference in mortality at 24 hours (210 24.1% vs 212 24.4%; odds ratio, 0.95; 95% CI, 0.59-1.52; P = .91) or at any other time point. On subgroup analysis, patients with severe injuries transported by police were less likely to be dead on arrival compared with matched patients transported by EMS (64 of 194 33.0% vs 79 of 194 40.7%; odds ratio, 0.48; 95% CI, 0.24-0.94; P = .03). For patients with penetrating trauma in an urban setting, 24-hour mortality was not different for those transported by police vs EMS to a trauma center. Timely transport to definitive trauma care should be emphasized over medical capability in the prehospital management of patients with penetrating trauma.