At 6:02 p.m. on wednesday, october 2, 2002, a 55-year-old white man who worked for the federal government was shot to death with a high-powered rifle in the parking lot of a grocery store in Glenmont, Maryland, just north of Washington, DC. A police station was just across the street from the scene of the crime, and an investigation began immediately. The police found a witness who remembered seeing two African-American males in a large, dark car leaving the scene, but there was no other information with enough detail to be useful.

The following day, the investigation became much more urgent when five more individuals were shot and killed in the Maryland suburbs north of the capital city using the same modus operandi – a high-powered rifle fired from a distant, unknown location. The victims were a mixture of age, gender, ethnicity, and occupation. All of the attacks took place outside, but they were at various types of locations including a car dealership, two gas stations, and a shopping mall. Witnesses provided no precise information about a possible perpetrator, but an individual did report seeing a white box truck speeding away from the scene shortly after one of the incidents. Again, there was no other evidence at the scene that was helpful.

What kinds of questions and analytic frameworks would help in catching the perpetrator as quickly as possible and preventing further killings?