Crime Lab Biological
The DNA Analysis Unit primarily receives evidence related to homicides, robberies, sexual assaults and property crimes. The DNA Analysis Unit may perform biological screening on evidence to test for the presence of blood, semen, saliva, urine and/or fecal matter. The samples can then be tested for two types of DNA extracted from body fluids, tissues, etc. Firstly, short tandem repeats (STRs) from nuclear (Autosomal and Y-STRs) DNA are analyzed to yield DNA profiles that are most familiar to the general public. Secondly, STRs only on the Y-chromosome (Y-STRs), a strand of DNA that is only found in males, are analyzed to yield male-specific DNA profiles. Y-STR profiles are particularly important in cases where men are specifically suspected of a particular crime (e.g. some instances of sexual assault) where their DNA may be mixed with a high quantity of female DNA. The Kern Regional Crime Laboratory was also one of the first Crime Laboratories in the country to use probabilistic genotyping software for the interpretation of DNA profiles. Probabilistic genotyping is a more informative method for interpreting DNA profiles from multiple contributors and/or those that are from a low quantity.
The DNA Analysis Unit also has the capability of performing Kinship Analyses. Using the same STR testing, the laboratory can test for maternity/paternity and for other possible genetic relationships which can be important in criminal and/or missing persons/unidentified remains cases.
The Kern Regional Crime Laboratory Database Program is an essential component of the Biological Sciences Section, because its staff maintains several databases that are critical to the interpretation and implementation of the DNA data produced by the laboratory.
The Kern Regional Crime Laboratory participates in the Combined DNA Index System (CODIS), which is administered by the FBI. CODIS is used to compare DNA profiles generated across participating forensic laboratories throughout the world in order to generate investigative leads in criminal and missing persons cases. CODIS may also be used to link serial crimes and unsolved cases with repeat offenders, which allows law enforcement and criminal justice agencies from multiple jurisdictions to coordinate their respective investigations and share the criminal case information that they independently develop.
The Kern Regional Crime Laboratory participates in the CODIS Hit Outcome Project (CHOP) which provides a mechanism for crime laboratories, law enforcement agencies and District Attorney’s Offices throughout California to share information and track changes in cases that contain DNA evidence submitted to local CODIS laboratories for forensic comparison. The California Department of Justice Bureau of Forensic Services, in partnership with the Western States Information Network, established this database as an extension of the CAL-DNA Data Bank. The laboratory also keeps information up-to-date in the Sexual Assault Forensic Evidence Tracking (SAFE-T) database as required by law.
Crime Lab Chemical
The Kern Regional Crime Laboratory Drug Testing Unit performs qualitative analysis on solid dose drug cases.
Analysts in the Drug Testing Unit examine materials for the presence of controlled substances as defined by California Health and Safety laws set forth in Schedules I-V (i.e. heroin, methamphetamine, phencyclidine and cocaine). Organic and inorganic chemistry as well as instrumental analysis is emphasized for handling case work. Regulated drugs may be presented as powders, solid material, liquids, blotter paper, as well as in plants or plant parts (i.e. marijuana, cactus buttons, opium poppies and mushrooms) and are packaged in a variety of containers. The Drug Testing Unit also examines pharmaceutical preparations including tablets, capsules, and injectables.
The Toxicological Analysis Unit manages Kern County’s forensic alcohol and breath analysis program, which encompasses alcohol/volatile testing for traffic-related offenses from blood, urine, and breath specimens. Breath alcohol analysis program personnel are responsible for training and certifying breath alcohol test operators as well as the maintenance and certification of the evidential breath test equipment used throughout Kern County. Oversight of the breath alcohol testing program by the laboratory ensures that state-mandated quality assurance and operational standards are followed by the county’s law enforcement agencies when they administer breath alcohol tests in the field.
Toxicological Analysis Unit scientists serve as a resource on matters that involve impairment and associated testimony for hearings and trials. Scientific support is provided to all county law enforcement agencies in the investigation of crimes where drug or alcohol use may be implicated.
Crime Lab Physical
Firearm and Toolmark analysis involves the analysis of the marks produced on one item by another item, such as a firearm or a tool. In regards to firearm analysis, the items with the marks generally include bullets, cartridge cases, shot shells, or other ammunition components. Toolmarks can be pry marks, cut marks, or other types of marks depending on the type of tool.
Firearm and Toolmark analysts at the Kern Regional Crime Laboratory examine evidentiary firearms to determine their class and unique individual characteristics for identification purposes as well as their functionality. Individual rifling characteristics of a firearm are imparted to the surface of a bullet as it travels down the barrel. The individual characteristics of the firing pin, breech face, extractor and ejector are imparted to the surface of the cartridge case when it is fired, depending on the type of firearm. Using the Firearm Database Search, firearm examiners are able to acquire, digitize, search and sort images of spent cartridge casings and bullets from crime scenes and seized evidence.
Firearm and Toolmark analysts also examine evidence tools to determine a tools class and unique individual characteristics for identification purposes. When a tool is used on an item or surface, it imparts the individual characteristics of the tool's working surface to that item.
Impression evidence belongs to a broad class of evidence which includes fingerprints, firearms and toolmarks, and shoe and tire track evidence that may be left behind at crime scenes. The Firearms and Toolmarks Unit of the Kern Regional Crime Laboratory analyzes all types of impression evidence, including shoe and tire impressions, that leave patterns when they come in contact with softer surfaces.Owing to the fact that impression evidence may be found on a variety of surfaces, including blood, the impressions left behind may be two or three-dimensional. Firearms and Toolmarks personnel at the Kern Regional Crime Laboratory work very closely with the Crime Scene Response Team to collect, preserve, and analyze this type of evidence so that little is lost from the scenes of crimes.