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Chemical Analysis

CL at Prep Hood

!! FIRE !!   !! EXPLOSIONS !!    !! CSI !!

Most of us have watched the various “forensic” shows on television. You know.  The ones where the ruggedly handsome CSI technician drives his brand-new Hum-Vee to the crime scene, pulls out a pocket knife, scratches a few bits of ash from the burned body, returns to the car, opens the trunk, slides the knife into a really sophisticated bit of electronics, and TA-DA…, a picture of the person who set the fire shows up on the TV screen. NOT LIKELY!! 

Remember, television shows are FANTASY. The real guys at the scene may have special training in how to select and preserve the evidence, but they typically do not also perform the actual analysis. None of the scene investigators we know have Hum-Vees. A real forensic lab employs scientists with special training and education who usually stay in the lab and run “instruments” all day long. Only a rare few are “ruggedly handsome”. 

Real forensic scientists have to take time to prepare the evidence so it can be properly tested by the correct instrument. The result they see is not a picture of the perpetrator, but data, usually in the form of squiggly lines. Cases are rarely solved within an hour like what is seen on TV. In the real world it can take significantly longer. The laboratory does not have every conceivable instrument (they are extremely expensive). They have to use the instruments on hand that provide the best information. That is where the scientist earns his or her pay. They have to be patient enough to get the most out of the evidence and they have to become experts at reading all those squiggly lines.

Evidence from fire and explosions are some of the most difficult types of forensic evidence to work with. Basically, you are trying to find a mixture of chemicals added to another mixture of chemicals. Sometimes the ones you are looking for are almost the same as the ones that were originally there.  How do you determine what was extra?  Can you say that the chemicals you find are really meaningful? It’s like having one of those abstract paintings with hundreds of colors mixed and overlapping. Only you are interested in just one specific hue of color. You have to be very talented to spot just that one hue against the multi-colored background. This is what the scientists in the Bureau of Forensic Services do every day. 

Strip in Hood

The goal of the Bureau is to provide timely and credible forensic analysis of evidence. The Chemistry Section achieves this objective through its analysis of: fire debris to determine the presence and identity of any ignitable liquids, explosives debris and residues to identify chemical components of the explosives, and non-drug chemicals recovered from clandestine laboratories. The presence of an ignitable liquid from the point of origin of a fire often aids investigators in determining the source of a fire. The identity of chemicals in explosive scenes and clandestine laboratories aids investigators with information critical to concluding their investigation. For calendar year 2013 covering the period of January 1, 2013 to December 31, 2013, the Bureau performed 9,347 chemical analyses for ignitable liquids, explosives, and hazardous chemicals.

RB at GC-MS RH at GC

Most evidence requiring fire debris, explosion, or other chemical analysis is submitted by the Bureau of Fire, Arson, and Explosives Investigations (73.9% of the samples submitted from July 1, 2013 to December 31, 2013). The Bureau also receives evidence from police departments (1%), fire departments (19.7%), and Sheriff’s Offices (5.4%) from across the State of Florida. Laboratory services are provided to all law enforcement or fire department submitters operating in the State of Florida without cost. Analysts will be made available for expert testimony provided a proper subpoena is presented.

Forensic evidence must be submitted to the Bureau either by hand delivery or via a certified carrier (United States Postal Service - certified mail only, Federal Express, United Parcel Service, etc.) (Evidence Submission Form DFS-K1-1096). Please be aware that there are federal as well as company specific restrictions regarding the shipment of materials. Specifically, you must be aware that certain items must be listed as "dangerous goods" and thus have special labeling requirements. Other items may have an "excepted quantities" variation.

Forensic evidence submitted to the Bureau will be returned to all submitters. Evidence is returned only after the samples are tested and a report is transmitted.

Bureau of Fire and Arson, and Explosives Investigations evidence is transferred to their Technician who will store it in the BFAEI Long-Term Storage areas within the facility. Should evidence be needed for court purposes, either the investigator or a court officer may request the evidence be shipped to them by contacting the BFAEI Evidence Technician, Brittney Geralds.

For specific requests as to evidence receipt, shipping, or transfer please contact Amy Pearson, Forensic Technologist or Chief Chasteen at the laboratory.

Evidence Submission PowerPoint