Maryland's system is passive and accesses, integrates, and analyzes data collected by the Office of the Chief Medical Examiner, the Maryland State Police, and the Division of Health Statistics. An evaluation of the system was conducted to assess the system's ability to ascertain cases in the absence of a standard for the true number of cases. The evaluation design was based on link records of the same firearm-related death captured by the system's multiple sources and a comparison of false positives and false negatives. The system was extremely sensitive in that it detected 99.61 percent of cases. It had a very high positive predictive value, with 99.87 of cases identified from medical examiner's office data being confirmed as actual cases. The authors conclude that Maryland's database of information from the medical examiner's office is highly accurate in identifying firearm-related deaths. Even so, they indicate that a unique identifier common across data sources may ease record linkage efforts and improve the system's ability to monitor firearm- related deaths. 4 references, 2 tables, and 3 figures