Appeals Court Rulings on Tasers Linked to More Fatal Police Shootings

🧭 Background — Legal Variation Over Time and Place

Jurisprudence about whether police use of electronic control devices (ECDs) counts as excessive force varies substantially across US states and across time. This variation includes year-to-year switches in how US Courts of Appeals treat the legality of ECD use.

🔎 Research Strategy — Exploiting Year-to-Year Switches in Appeals Court Rulings

A generalized difference-in-differences design is used to estimate the effect of court-level changes in ECD legal restrictiveness on police use of force. The identification leverages temporal and cross-jurisdictional variation in Courts of Appeals decisions—specifically year-to-year switches in doctrinal restrictiveness regarding legal ECD use.

📊 What Was Measured

• Treatment: switches in judicial restrictiveness about the legal use of ECDs at the US Courts of Appeals level.
• Outcome: lethal police force, measured as the number of civilians shot and killed by police officers.
• Empirical approach: generalized difference-in-differences to compare changes before and after appellate switches across affected and unaffected jurisdictions.

📈 Key Finding

• Switches toward greater judicial restrictiveness on ECD legality are associated with an increase in the use of lethal force, as captured by more civilians shot and killed by police officers.

⚖️ Why It Matters

These results link shifts in appellate doctrine about nonlethal devices to real-world outcomes in police lethality. The findings suggest that changing legal standards for ECDs can have unintended consequences for escalation and fatal force on the streets, with implications for courts, police policy, and oversight mechanisms.