Submission FAQ
Biology



What types of cases does the Biology/DNA section work?

A: The Biology/DNA section accepts evidence from all types of crimes including both violent and non-violent offenses. Please see the FDLE Crime Laboratory Evidence Submission Manual Biology section for the type of evidence accepted for different crimes. If unsure whether or not a case will be accepted contact the regional Biology supervisor.


Is Biology testing conducted on burglary or non-violent crimes?

A: YES, please access our Crime Laboratory Evidence Submission Manual to review what is accepted for these types of crimes.


Why is evidence submission policy necessary for Biology?

A: FDLE developed the Case/Evidence Acceptance Policy for Biology in 2007 in an effort to reduce the turn-around time for completing cases and to help streamline the analysis process. Ultimately, it means results are released faster. The policy promotes the identification and submission of the best evidence first. For complex cases, the regional supervisor can be contacted to assist in identifying the best evidence for approving exceptions to the policy.


What are the case acceptance limits for homicides?

A: Access the FDLE Laboratory Submission Manual  Biology Case/Evidence Acceptance Policy to obtain this information. As with any case, contact your regional supervisor with any questions and/or possible exceptions that may be needed.


Are there certain types of evidence not accepted by FDLE Biology?

A: Yes. There are some types of evidence Biology will not accept such as vomit, feces, urine. Also, at this time fired cartridges are not accepted for DNA processing.


For cases or evidence not accepted by FDLE, is there another
laboratory that will work it?

A: There may be private accredited laboratories who can work the evidence not tested by FDLE. The FBI laboratory may also be able to conduct some of the analysis. Other sections of the FDLE laboratory, like Friction Ridge or Firearms, may be useful for the case/evidence. Cases that involve unidentified human remains, missing persons or kinship testing are referred to University of North Texas Center for Human Identification. Contact your regional supervisor with any questions.


What method of forensic DNA testing is conducted by FDLE?

A: FDLE conducts short tandem repeat (STR) DNA testing. DNA is composed of four bases: A (adenine), T (thymine), G (guanine) and C (cytosine). Individuals have within their DNA code repeated locations (loci) made up of core sequences of the bases. The number of times these core sequences repeat (STRs – short tandem repeats) varies between individuals. All individuals, except identical twins, have a unique pattern, distinguishable from all others. STR DNA analysis is considered the most reliable method for determining identity of an unknown suspect. FDLE also conducts Y-chromosome STR DNA testing. This testing detects repeating locations found only on the Y-chromosome. Only male individuals have a Y-chromosome, and unlike the STR testing just described, male patrilineal relatives will all have the same Y-STR DNA pattern, unless there is a mutation in the DNA.


When would Y-STR testing be used?

A: Y-STR testing is useful in cases involving a female and male where the quantity of the female's DNA is so high that it is masking the DNA from the male, and where no other probative information has been obtained from the DNA testing in the case. The case working analyst will indicate in their report if samples are suitable for Y-STR testing.


How long does forensic DNA analysis take?

A: The turn-around-time (TAT) for forensic analysis is very case dependent. Cases with a single item of evidence, like a burglary, can be completed much more quickly than a case with many items of evidence, like a homicide. TAT is also impacted by the workload and staffing of the laboratory. F.S. 943.326 requires the testing of sexual assault evidence kits to be completed within 120 days. All FDLE laboratories are successfully meeting this requirement with a TAT well below 120 days. Rush requests may be submitted to each regional supervisor for time sensitive cases.


Can Biology determine when or how a stain or DNA is deposited?

A: No, current test methods are not able to determine how long the stain or DNA has been present or under what circumstances it was deposited.


Can you tell any physical characteristics about a person from
STR DNA testing?

A: No, there is no genetic, health, or disease susceptibility information in the DNA analysis of the forensic STR locations. The testing conducted in the FDLE laboratory provides a STR profile that can be used, in conjunction with a database, to provide investigative leads. The DNA profiles between known and evidence samples can also be compared to link individuals to crime scenes or items collected from them.


Is it recommended that items of evidence be sent for Biology
analysis before being sent to other sections for processing?

A: Yes, for most items. Below is the processing order followed by FDLE:

  • Biology before Friction Ridge, Firearms, Digital Evidence or Seized Drugs
  • Trace Materials before Biology, Friction Ridge or Firearms
  • Toxicology before Biology or Seized Drugs

 


How does evidence flow through the Biology lab?

A: Once the case has been accepted into the laboratory, it will be assigned to a Biology Crime Laboratory Analyst (CLA) to be worked. Evidence is first visually examined and if applicable screened for body fluids like blood, semen or saliva. Cutting(s) and/or swabbing(s) are collected from the evidence and then the DNA process beings. This includes breaking open cells to release the DNA, finding out how much DNA is in the sample, making millions of copies of specific locations on the DNA and then using an instrument to visualize the DNA. The DNA results look like peaks on a graph. The CLA interprets all of the DNA data to make determinations about the samples. These are then included in the report. The case file and report go through a technical and administrative review.  Once the reviews are completed, the report is released to the submitting law enforcement agency and the applicable state attorney's office.


What is touch DNA, wearer DNA, handler DNA and drinker
DNA evidence?

A: FDLE defines touch DNA evidence as that which typically has no visible staining and would contain DNA resultant to brief contact with an item such that sweat and/or skin cells may transfer. This is not prolonged contact. The collection of touch DNA evidence is only recommended where a high degree of likelihood exists to provide probative results or investigative leads. The use of witness corroboration, visual monitoring systems, or sound deductive reasoning may aid in determining its value for DNA analysis.

Wearer and handler DNA evidence can be defined as that which may or may not demonstrate visible staining and would contain DNA as a result of prolonged contact and/or friction with an individual (i.e. collar of a shirt, sweat band of a hat, handle of a weapon). Elimination standards must be submitted where appropriate.
 

Drinker DNA evidence is resultant from a suspect drinking from something, such as straws or bottles, is not considered touch DNA due to expected saliva.

What is CODIS?

A: CODIS is the acronym for the Combined DNA Index System and is the generic term used to describe the FBI's program of support for criminal justice DNA databases as well as the software used to run these databases. It is a multi-tiered system consisting of the National DNA Index System (NDIS), State DNA Index System(s) (SDIS) and Local DNA Index System(s) (LDIS). NDIS contains the DNA profiles contributed by federal, state, and local participating forensic laboratories. The following link provides additional information about CODIS, including the current composition and statistics of the CODIS system https://www.fbi.gov/services/laboratory/biometric-analysis/codis.

Each regional laboratory maintains a LDIS which collects DNA profiles generated from crime scene samples including suspect standards. Qualifying DNA profiles from LDIS are uploaded to Florida's SDIS which contains qualifying offender profiles for comparison. Finally, SDIS profiles which meet completeness criteria are uploaded to the national level (NDIS). All three tiers of CODIS employ routine searches which compare crime scene profiles against known profiles (i.e. arrestee, offender and, suspect) as well as to other crime scene profiles. These searches may generate investigative leads via a CODIS hit .

FDLE houses the DNA Investigative Support Database, which processes the samples collected from qualifying offenders as defined in F.S. 943.325. Florida's database is the 2nd largest in the United States and contains over 1 million qualifying offenders, with over 6,000 qualifying offenders added each month.


Does CODIS have specific requirement for entry of a DNA profile?

A: Yes, there are several requirements for the DNA data submitted to CODIS:

  • The DNA profile must be from biological material from the crime scene evidence associated with the commission of a crime;
  • The DNA profile must be from the putative perpetrator and the evidence not collected from a suspect's possessions.
  • The DNA profile results must meet minimum CODIS requirements for entry.
The REMARKS section of the Biology reports will include information pertaining to CODIS.

 


Can DNA samples or profiles maintained in CODIS be accessed
by anyone?

A: No, the Federal DNA Act 34 U.S.C. §12592(c) and Florida Statute 943.325 limit access to DNA records and DNA samples.


Can the arrestee or offender sample collected for entry into the
DNA Database as a requirement of 943.325 be used by the
local FDLE laboratory?

A: No, that sample is collected for entry into the Florida DNA Investigative Support Database, which is a part of CODIS, and can only be used for that purpose per the Federal DNA Act 34 U.S.C. §12592(c) and Florida Statute 943.325.


Why does the local laboratory require a buccal swab following a
CODIS match to an offender?

A: A buccal swab collected through a search warrant or court order and submitted to the local regional laboratory allows for, in most cases, a single analyst to testify to all of the testing in the case, along with the strength of the DNA match that is made. Additionally, samples entering the DNA Database are not considered items of evidence and an individual chain of custody is not established and are typically inadmissible at trial.


Why isn't a Possession of a Firearm (or Ammunition) by a
Convicted Felon (PFCF) case eligible for CODIS entry or search?

A: The subject's DNA is reasonably expected to be on the firearm and is not eligible for a CODIS entry or search as a forensic unknown profile, however, a subject's known DNA standard could be directly compared to any DNA generated from a firearm without a CODIS entry or search.


How is each regional Biology section staffed and what is
each member's role?

A: Each Biology section is staffed by a combination of Crime Laboratory Analysts and Forensic Technologists. Crime Laboratory Analysts primarily handle the analysis of items of evidence submitted to the laboratory and will generate reports to their results. They are commonly called to testify in the counties their laboratories serve. Forensic Technologists operate and maintain equipment and stock supplies for each laboratory. They are in a supportive role. Each laboratory will also have CODIS administrators (Crime Laboratory Analysts) who maintain the LDIS and verify matches and entries to the DNA database. The regional biology laboratories are supervised by at least one Crime Laboratory Analyst Supervisor (CLAS) and a Technical Leader (TL). Each CLAS performs administrative review of casework, releases completed reports, and assigns cases as they are submitted to analysts. Technical leaders oversee the quality aspects of the laboratory and maintain uniformity across the lab system by updating standard operating procedures and tracking laboratory quality reviews.


What is NGS/MPS testing and does FDLE conduct this type of
testing?

A: Massively Parallel Sequencing (MPS), also referred to as Next-Generation Sequencing (NGS), is a high-throughput method used to sequence DNA. Current forensic DNA analysis at FDLE focuses on DNA fragment-length variation between individuals at short tandem repeat (STR) locations. Since MPS results are at the base-pair level, it has the ability to resolve DNA types that are identical by size but different in sequence. Data generated from MPS is compatible with the STR data, targeting the CODIS loci and Y-STR markers currently used, as well as additional STR markers, all in a single test. Identity, ancestry, and phenotypic single nucleotide polymorphisms (SNPs) are also targeted, which may provide additional information to investigators. FDLE is currently in the process of implementing this technology.