| Evidence Packaging Evidence Swabs- Package swabs collected from different areas into separate swab boxes.
- Label each swab box with the location collected and the case number.
- Place all swab boxes into a paper envelope and seal the envelope with evidence tape.
- Label the envelope with your initials, date and offense number; be sure to write across both the tape and envelope.
Actual Evidence Items- Full evidence items may be collected in lieu of swabs.
- If fingerprints are suspected to be on the item, submit the item for fingerprint processing FIRST. After fingerprint processing, you can submit the items to the Institute’s Forensic Genetics Laboratory for DNA testing and analysis.
- Package items separately in paper bags or containers, ensuring all items are dry prior to packaging.
- Wet items must be dried prior to packaging or may be TEMPORARILY packaged in plastic for transport.
- If wet items are to be submitted to the lab in plastic, be sure to clearly indicate this on the outermost package so that the item can be dried upon arrival.
- Seal each bag or container with evidence tape.
Label each package with your initials, date and offense number; be sure to write across both the tape and package.
Buccal Swabs- Collect at least two swabs from each individual, having the individual rub the swabs on the inside of his/her cheek. Place the swabs inside a swab box.
- Label each swab box with the name of the person from whom the swabs were collected, date, your initials and the case number (or offense number).
- Package swabs from each person in a separate box.
Place all swab boxes into a paper envelope and seal the envelope with evidence tape. - Label the envelope with your initials, date and case/offense number; be sure to write across both the tape and envelope.
Go To Top | | Evidence Packaging Drug evidence must be submitted inside an evidence container, such as a sealed evidence bag (paper or plastic), envelope or box. It is acceptable to include multiple pieces of drug evidence in one evidence container if the evidence is separated within it. When using paper bags, envelopes or boxes, each seam must be sealed with tamper-evident evidence tape. All seals must be initialed or otherwise marked to document the person sealing the evidence. Be sure to write across both the tape and envelope. - At a minimum, the evidence container must be labeled with the name of the submitting law enforcement agency and agency case number.
- Syringes and sharp objects must be submitted in sealed plastic puncture-resistant containers.
- All liquid evidence must be sealed in a leak-proof container.
- All plant material must be dried prior to submission to the laboratory.
- Fresh suspected khat plant material must be refrigerated. Dried suspected khat plant does not require refrigeration.
- Mushrooms must be submitted in a paper bag or envelope.
Weight LimitationsNo more than 100 pounds of suspected marihuana or 20 kilograms of any other substance may be submitted per case for in-house analysis by the Institute. If the evidence weight exceeds these amounts, core sampling will be performed by Institute laboratory personnel at an off-site location designated by the submitting agency. Purity/Quantitative AnalysisPurity testing (also known as quantitative analysis) is performed as required by Texas Law on liquid preparations of codeine and hydrocodone. Go To Top | | Evidence Packaging For full toxicological analysis, it is recommended that the submitting agency provide the following: - Blood – A total of at least 14mL of blood collected in two test tubes with sodium fluoride and potassium oxalate preservatives, i.e., gray-topped tubes (best for DWI)
- Urine – 50mL of urine collected in a urine specimen bottle or urine specimen cup (best for Drug Facilitated Sexual Assault)
Evidence PackagingEach specimen tube, bottle or cup must be labeled with the following: - Name of the individual from whom the specimen was collected
- Date and time of collection
- Initials of the individual who collected the specimen
Each specimen tube, bottle or cup should be stored inside a specimen container, such as a cardboard box, envelope or plastic bag. It is acceptable to include multiple specimen tubes, bottles or cups in one specimen container if they all pertain to the same case. The specimen container should be sealed with evidence tape and must be labeled with the following: - Initials of the individual submitting the specimen container – initials must be written across both the tape and the container
- Name of the submitting law enforcement agency
- Case number
To maintain the integrity of the specimen, a chain of custody should be initiated upon collection and the specimen should be refrigerated as soon as possible. Result Reporting for DWI TestingIn suspected Driving While Intoxicated (DWI) cases, blood specimens first undergo alcohol testing. If the blood alcohol level is greater than or equal to 0.10 g/100mL, no further testing is performed unless specifically requested. If the blood alcohol level is less than 0.10 g/100mL, drug screening and confirmation is performed. When the recommended volume of blood or urine is not received, some testing may not be possible. For example, when the specimen sample volume is not sufficient for both drug screening and confirmation tests, positive screening results will be reported as “Presumptive positive.” In these instances, a forensic toxicologist may contact the submitting law enforcement agency to discuss the need for drug confirmation tests. When sample volume is not sufficient for any type of testing, results will be reported as “Quantity not sufficient.” Go To Top | | Evidence Packaging Gun Shot Residue Evidence- Only GSR stubs can be accepted for analysis. Swabs, clothing, and other items cannot be analyzed and will be returned to the agency.
- Suitable forms of packaging for GSR evidence include manila envelopes and evidence bags, including brown paper and clear plastic types.
- The evidence package should be sealed with evidence tape and must be labeled with the following:
- Initials of the individual submitting the specimen container – initials must be written across both the tape and the container
- Name of the submitting law enforcement agency
- Case number
Fire Debris Evidence- Fire debris evidence must be submitted in air tight containers, such as metal cans. Other forms of packaging, such as evidence bags, will not be accepted.
- Each item number should be packaged in a separate container.
Note: Fire debris evidence is accepted only during business hours.
Firearms Evidence- For safety reasons, firearms will only be received in clear plastic bags or gun boxes with a viewing window.
- All firearms should be made safe by inserting a cable/zip tie in the action to render it inoperable.
- Ammunition should be packaged separately from the firearm.
- The evidence submission form should clearly indicate the type of analysis that is being requested.
- Firearms may not be left in the after-hours drop box. Firearms may only be submitted in person between 8 a.m. and 5 p.m., Monday through Friday.
- Some circumstances, such as a firearm recovered from and submitted in water or a firearm that is loaded that cannot be made safe, will require special handling or attention. When this situation arises the Firearms Section should be notified directly so that appropriate accommodations can be made.
- If additional clarification or assistance is needed please contact the Firearms Section at
(713) 796-6750.
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