Acting alone, Laurie Dann shot six young children in an elementary school, killing one, in Winnetka, Ill. She also shot a man in his home and set fire to another local residence. The Winnetka police department was a member of a formal mutual aid group of 42 law enforcement agencies and was able to use the group's resources to handle the case successfully. The effort involved a total of 2,352 hours by evidence technicians and an initial response team during a 14-day period. The FBI and the Illinois Division of Criminal Investigation also provided technical assistance. The events show that a written mutual aid pact can provide extra personnel and resources as well as an automatic and systematic response while outlining responsibilities and liabilities. Photographs, additional case example, and address and telephone number from which to obtain more information