General Lab FAQ
Look up your case number on the prelog site to see the status of your case. If additional information is needed, contact the Evidence Room.
The majority of analysts at the Iowa DCI Crime Laboratory possess a four year degree in a physical science in areas such as biology, chemistry, genetics, biochemistry or similar degrees. These degree paths are sometimes coupled with forensic themed programs or focus. A good portion of our staff also possess advanced degrees in their chosen field of study. This laboratory puts a large amount of importance on laboratory skills, scientific knowledge, teamwork and stakeholder focus. An internship in a forensic laboratory or a related scientific field is also recommended.
Yes. If you are interested in an internship opportunity, please contact labintern@dps.state.ia.us.
DNA Casework Section FAQ
DNA is an acronym for the genetic material deoxyribonucleic acid. DNA is used by the body to determine whom an individual is, everything from physical features to personality. DNA is found in all nucleated cells of the body. One half of a person’s DNA comes from their mother and the other their father. This combination is what makes an individual unique with the exception of identical twins. The DNA found in an individual's blood is the same DNA that is found in their saliva, tissue, bone, etc.
DNA testing or "profiling" is used to identify a potential source of biological evidence by matching questioned samples (left at crime scenes) with known samples from victims and suspects. For example, when a sexual assault occurs and seminal fluid is left on the vaginal samples of the victim, it is possible to compare the DNA profile obtained from the semen donor to a known DNA profile from a suspect. Since the DNA profile from the suspect's semen will be the same as that of his known saliva or blood, a match will link a suspect to a crime.
Blood and semen are most commonly tested but they are not the only possible sources of DNA. Saliva, sweat, vaginal fluid, hair (with suitable root structure), muscle tissue, and bone may also be tested. Urine and fecal samples may contain small quantities of DNA but are poor sources for testing.
All samples should be collected using appropriate collection procedures to avoid sample destruction or degradation. Additionally, every precaution should be taken to avoid contaminating the biological sample upon collection. Biological material is best preserved in a dry, cold environment. All items should be packaged separately into paper bags or envelopes.
DNA Evidence Collection at Crime Scenes is a pdf file containing information from the Criminalistics laboratory regarding the collection of evidence. This can be found at the bottom of the DNA Casework Section page.
For more information on collecting and packaging biological samples please visit the following website:
FBI Handbook of Forensic Services
Known reference samples are most commonly submitted as either buccal swabs or as dried blood samples. When possible, known reference samples should be provided at the same time as the questioned evidentiary material. (Submitting agencies, please state on the case submission form if no known suspect sample is available and why.)
Buccal swab(s) should be collected by scrubbing a clean and dry cotton swab on the inside surface of the cheek and gums. It is advisable to collect at least two swabs and to allow the swabs to air dry in a breathable swab box, paper envelope, or appropriate container. Identify the buccal swabs with the appropriate information and submit them to the lab in a timely fashion. The dry buccal swab does not need to be refrigerated.
The known dried blood sample should be collected by drawing blood (by qualified medical personnel) on to a filter paper card using a finger stick collection device and having the blood sample blotted off the fingertip on to an appropriate filter paper card and air dried. Place the dried blood card into a paper envelope and seal. Identify the blood sample with the appropriate information and add biological identifier/hazard labels as appropriate. The dried blood sample does not need to be refrigerated. Submit the sample to the lab in a timely fashion.
Yes. "No Suspect" crimes against persons should be submitted for testing. In many cases DNA evidence left at the scene may be the only link to potential perpetrators. The DNA profiles obtained from "No Suspect" cases may be placed into a computer database and searched against DNA profiles from convicted offenders as well as evidentiary samples from additional "No Suspect" cases. Submitting agencies please state on the case submission form if “no suspect is identified”.
The Federal Bureau of Investigation facilitates the use of a national DNA database called CODIS. CODIS is an acronym for the Combined DNA Indexing System. It may be used for DNA profile searches within the state of Iowa as well as across the United States. DNA profiles uploaded to CODIS with less genetic information may only be searched within the state of Iowa.
CODIS has proven to be an effective tool for providing investigative leads to law enforcement agencies. This is particularly true when no suspect has yet been developed. Upon entry into CODIS a DNA profile may be compared to DNA profiles obtained from Crime Laboratories across the country for potential matches. This exchange of information allows a DNA profile from one crime scene to be linked to a separate crime scene in a different jurisdiction. Additionally, CODIS eligible DNA profiles will also be compared to DNA profiles obtained from individuals convicted of qualifying offenses.
When a DNA match is found in CODIS and it provides information that the case officer previously did not know, it is called a “hit”. When a CODIS hit occurs, a CODIS match report may be issued to the agency or agencies involved. There are two types of CODIS match reports, the Forensic hit report and the Offender hit report. A Forensic hit report is issued when a DNA profile from a crime scene matches a DNA profile obtained from a separate crime scene. An Offender hit report is issued when a DNA profile from a crime scene matches a DNA profile obtained from a convicted offender.
As the number of profiles in convicted offender databases increases, the number of "cold hits" or matches to "no suspect" cases increases. Currently, enormous backlogs of convicted offender samples are unanalyzed in the USA. Substantial reduction of these backlogs is expected in the next few years depending on available funding.
A DNA profile becomes CODIS eligible when it is obtained from biological material collected from a crime scene and is attributable to a presumed perpetrator.
To assist the laboratory in determining whether a submitted item may be eligible for CODIS, the laboratory requests that submitting agencies provide a specific description of where the item was collected and to whom the item belongs if known. This description should be recorded on both the outer packaging of the item as well as the evidence pre log. Until this information is provided by the submitting agency DNA profiles may NOT be eligible for entry into CODIS. Please fill out the DNA Case Information Form when submitting DNA evidence.
Providing sufficient detailed information about a submitted item will expedite its entry into CODIS. The following list shows descriptions of preferred wording to use when submitting items for DNA testing:
“The swab of blood was collected from the point of entry/exit at the burglary scene. The victim states that the blood is not theirs and was not there prior to the incident.”
“The cigarette butt was collected from inside the burglary victim’s residence. The victim is a non-smoker.”
“The suspect’s mask was collected from the path of exit from the bank. The mask does not belong to any of the employees or anyone in the bank at the time of the burglary.”
“The beverage container was collected from inside the victim’s vehicle. The beverage container does not belong to the victim.”
“The gloves were collected from inside the victim’s residence. The gloves do not belong to the victim.”
Additionally, please describe any known relationships between the victim and suspect (husband/wife, boyfriend/girlfriend, etc). Submitting agencies are encouraged to provide this information in the "Case Comments" section of the pre log.
Please be aware that some items submitted for DNA testing may not be eligible for entry into CODIS. To become eligible for CODIS an item must be collected from a crime scene and also be attributable to a presumed perpetrator. The following are examples of submitted items that would not be eligible for CODIS:
- DNA profiles obtained from known reference DNA samples. Known reference DNA samples are items such as buccal swabs (note: buccal refers to the inner oral cavity) and blood cards collected directly from individuals believed to be involved with the case. Known reference DNA samples should be provided when possible for comparison purposes. However, because these items are not crime scene evidence they cannot be entered into CODIS.
- A suspect puts out a cigarette in an ashtray at a restaurant and the cigarette butt is submitted for DNA testing. Assuming the suspect has not committed a crime while eating lunch, the cigarette butt is not crime scene evidence and therefore ineligible for CODIS entry.
- A victim’s DNA profile is obtained from stains located on the suspect’s bloodstained shirt. This information may be of probative value for investigative purposes, but because the victim is not the presumed perpetrator for the case, the DNA profile obtained from the shirt is not eligible for CODIS.
- A suspect’s DNA profile is obtained from bloodstains found on the suspect’s own item of clothing. Because the clothing was seized directly from the suspect, DNA profiles obtained from such items are not eligible for entry into CODIS.
- An incomplete or “partial” DNA profile may be obtained from an item deemed CODIS eligible. However, because the DNA profile was not complete, there may not be sufficient data to support entry into CODIS.
DNA PCO Section FAQ
- The collector should swab the offender when collecting DNA samples. Do not let them swab themselves.
- If an offender's sample must be re-collected, please follow the normal protocol for entry of that offender. If you encounter any issues when entering that offender on the website, please contact the Crime Lab.
- A second offense violation of section 321J.2, unless the person has more than one previous revocation as determined pursuant to section 321J.2 (OWI) subsection 8 within the 12-year period immediately preceding the commission of the offense in question.
- A violation of chapter 716B. (Hazardous Waste Offenses.
- A violation of chapter 717A. (Agricultural Production Offenses)
- A violation of section 725.7. (Illegal gaming)
As long as all identifying information (DOB, SSN, DOC, DCI) match that sample does not need to be collected. The offender entry website will not allow you to collect enter an individual based solely on a name change. The system will flag the sample as a duplicate unless a re-collection is required.
NO. These kits are only for the Convicted Offender Unit not for casework.
The kits are provided by the Iowa DCI Crime Laboratory, and are distributed to local law enforcement agencies by the Department of Corrections. Please contact Abby Williams (abigail.williams@iowa.gov or 515.725.5746) to receive more DNA collection Kits.
Drug Identification Section FAQ
A controlled substance is a drug or chemical whose manufacture, sale, possession or use is regulated by state and federal laws. The Controlled Substances Act (CSA) classifies drugs into five schedules. This scheduling is dependent on the drug’s acceptable medical use and the drug’s abuse or dependency potential.
Powders, liquids, tablets, crystalline substances, pipes, cigarettes, consumables, transdermal patches, paper items, and plant material can all be submitted for analysis.
Methamphetamine may be analyzed for purity if the case is for federal prosecution and samples weigh over 1 gram or for clandestine laboratory cases. Purity analysis can also be done on phencyclidine (PCP) samples for federal prosecution or PCP cases, other than possession, in which the net weight is more than 10 grams.
Generally, only a small portion of the sample would be taken for testing leaving at least half if possible. If the original sample is a residue, or a very small amount, then the whole sample may be used and the sampled material would be returned to the evidence package after analysis.
The Hypergeometric Sampling Plan is a statistically based sample model which allows the analyst to analyze only a portion of the sub-items submitted and subsequently make statistical inferences about the entire population.
The sampling plan is used when there are a large number of sub-items and the sub-items are visually similar to each other. The selection is random among the population and analysis is done on the selected sub-items.
Field test kits are only presumptive tests and therefore are not specific. This means that other substances may cause a reaction similar to a controlled substance. Field test kits are also sensitive to extreme heat and have expiration dates. It is advised that field test kits are kept at room temperature and are not used after the expiration date. Also, after adding the sample, observe color change only up to one minute. Most kits contain acids that will char the substance over time.
Yes, however, it is encouraged to take pictures of the plants with their root systems then submit only a sample of the dried leaf material from each plant in separate packaging. For large grow operations, please contact the drug section for direction.
Containers with anhydrous ammonia are not accepted. Labeled containers of muriatic acid or sulfuric acid are discouraged. Similarly, acidic liquids or liquid/solid mixtures from unmarked containers and from used HCl generators are also discouraged. Items, such as batteries and instant cold packs that are factory sealed need not be submitted. If excessive numbers of coffee filters with residues are present, a representative sampling of the group can be submitted and the remainder documented by photographs. An inventory of pseudoephedrine tablets or empty tablet packaging can be submitted in lieu of the actual items.
A call to the Laboratory is suggested when there is uncertainty on the part of the submitter. Liquids should be placed in glass jars. Solids that are wet or damp should also be in glass jars. Dry solids can be stored in either glass or plastic containers. The preference for the outermost packaging of liquids and solids from clandestine laboratories is a plastic bucket with a tight lid. This will keep fumes from surrounding areas and retain liquid, if leakage occurs. A strong box is acceptable, if a plastic bucket is not available.
Evidence Room FAQ
All biological specimens are held for a minimum of 90 days after testing is complete. If you need a sample preserved you must contact the Evidence room and that sample will be returned to your agency. It is not possible for the laboratory to store biological materials on a long-term basis.
- Iowa State Patrol (ISP) cases only: Yes. The Crime Lab will maintain the chain of custody and send the sample to another lab for testing. You must indicate this in writing where you want the sample to be sent and the address. Contact the Evidence Room to make arrangements.
- Non-ISP cases: No. The Crime Lab will return the evidence to your agency, upon written request, for your agency to send to a private lab.
The Crime Lab is not responsible for cost associated with independent testing.
Impression Evidence Section FAQ
ABIS stands for the Automated Biometric Identification System. ABIS serves multiple functions, including acting as a repository for known fingerprint and palm print records. At the DCI Crime Laboratory, the Impression Evidence Section utilizes ABIS to facilitate the search and potential identification of unknown latent prints.
The state ABIS system is currently contracted through IDEMIA. This software provides latent print examiners across the state access to not only the Iowa database, but also Next Generation Identification (NGI), the federal database maintained by the Federal Bureau of Investigation.
The ULF is a repository within an automated database system (i.e. ABIS, NGI) of latent prints which remain unidentified after initial search. Latent prints retained in the ULF are routinely searched against new incoming known records. A reverse hit occurs when a latent print retained in the ULF displays sufficient agreement with a candidate respondent such that they are determined to be have originated from the same source. A reverse hit is equivalent to an identification.
Latent prints saved to the unsolved latent file (ULF) may be removed at any time due to a variety of reasons, including but not limited to statutory limitations and identifications resulting from other database searches or manual comparisons.
Toxicology Section FAQ
Yes, additional testing is possible as long as there is sufficient quantity of sample, the DCI tests for the drug of interest, the DCI still has the evidence, and it hasn't been destroyed.
Metabolites are formed as part of the natural biochemical process of degrading and eliminating the compounds from the body. Some drugs pass through the body intact while others may be partially or totally metabolized to another form to facilitate elimination. Thus a confirmation report may indicate the parent drug was identified, or it may indicate that a metabolite of the parent drug was identified or it may indicate that both were identified.