Criminalistic laboratory investigations

There are wide variations in the nature and magnitude of the caseload and in the manpower and technical capabilities of the nation s criminalistics laboratories (Peterson). Ideally, the crime scene itself should be surveyed by a trained criminalist who is also responsible for the proper collection and transmission of physical evidence. Unfortunately, this practice is only found in the most advanced criminalistics operations, and even here it is almost entirely restricted to major crimes (bombings, homicide, suicide, hit-and-run auto deaths, etc.). While this approach will never be practical for the investigation of all criminal acts, it would permit realistic collection of evidence and its proper transmission to the laboratory for scientific evaluation. The criminalist must be aware of what he is looking for and of the accuracy, precision, and investigative significance of his measurements. 

The final paper in this volume (Jones) is concerned with the application of a less familiar technique, photoluminescence, to a wide range of investigations, including sensitive firearm residue detection, the discrimination between different glass, polymer, and hair samples, and the identification of seminal stains. The promise here is of relatively inexpensive equipment with wide applicability in the criminalistics laboratory. 

Measures of effectiveness. Concurrent with the research to develop measures of performance, the Calspan Corporation has been developing techniques for measuring the effectiveness or impact of crime laboratories on the criminal justice system. Prior to this study the various uses of criminalistics in criminal justice operations have not been evaluated quantitatively and on a crime-specific basis. Even though crime laboratories have expanded and increased in number in recent years, there is little information which shows that the quality and scope of laboratory output is satisfying the practical needs and expectations of investigators, attorneys and the courts. 

The integrity of the evidence must be preserved in criminal investigations, and it seems preferable to examine as much physical evidence as possible in local and regional laboratories so that the complexity of the overall criminalistics process can be minimized. Each laboratory should be well managed and adequately staffed by competent, scientifically trained criminalists who are given the opportunity and encouragement continually to upgrade their education and expertise. 

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