UNTCHI Evidence Unit
Click here for a list of Frequently Asked Questions related to DNA submissions and analyses.
UNT Center for Human Identification
Attention: Evidence Custodian
CBH 6th Floor
3500 Camp Bowie Boulevard
Fort Worth, TX 76107
Forensic or Missing Persons evidence/samples can be submitted to UNTCHI using the mailing address listed below. Agencies can also drop off or pickup evidence onsite by scheduling a time thru the Evidence Specialists. All samples should be submitted with appropriate UNTCHI submission paperwork which are available for downloading below.
The following provides a basic outline for case and sample types accepted by the laboratory for biological screening and/or DNA analysis. The evidence custodians will review submissions to determine if the evidence submitted falls within these acceptance criteria. Please contact the Evidence Specialists if you have questions regarding acceptability, submissions or collections.
Missing Persons: Direct Reference Samples
The following are considered acceptable direct reference samples:
(a) Medically obtained blood cards, whole blood, or a tissue specimen that was collected from the missing person (Preferred)
(b) A toothbrush used only by the missing person (Preferred)
(c) Oral appliance, e.g., retainer, dentures, etc. worn by the missing person
(d) Hair of the missing person (Least Preferred)
Eyeglasses, caps/hats, stained clothing, make-up, any biological stain of unknown origin,
cuttings or swabs from any of these items, forensic unknowns, etc., are not considered
acceptable for testing as direct reference samples for missing persons cases.
Missing Persons: Family Reference Samples
The following are considered acceptable family reference samples:
(a) Buccal swabs (Preferred)
(b) Blood card or whole blood
The family reference samples submitted should include at least one maternal relative for mitochondrial DNA analysis.
The preferred order for the submission of family reference samples is as follows:
(a) Mother, Father, and/or Child of the missing person (Most Useful)
(b) Full sibling of the missing person (Useful)
(c) Half-sibling, Aunt/Uncle, Niece/Nephew, Grandparents
of the missing person (Least Useful)
UNTCHI provides FRS collection kits to submitting agencies at their request.
Family reference samples (FRS) are collected by law enforcement with signed
voluntary consent of the donor.
Missing Persons: Unidentified Human Remains
The following are acceptable for testing of human skeletal remains (listed in order of preference):
(a) Long bones (e.g., femur, tibia, humerus), metacarpals, and metatarsals (Most
(b) Mandibles, teeth, shorter bones (e.g., ulna, radius, clavicle)
(c) Vertebrae, ribs, pelvis
(d) Skull (Least Preferred)
Non- skeletal samples, e.g., blood cards, whole blood or tissue are also acceptable.
The following samples are not accepted:
(a) Paraffin-embedded tissue samples.
(b) Embalmed remains.
(c) Burned remains. These samples may be accepted on a case by case basis depending on the extent of the thermal damage.
(d) Samples unknown to originate from a unidentified person or decedent.
A medical examiner, coroner, anthropologist, or police/investigative report must accompany the submission of skeletal remains. If this report is not available, UNTCHI can provide forensic anthropology services.
Missing Persons: Unidentified Living Person Samples
Unidentified Living Person samples (ULP) are collected from individuals who either through age, mental illness or circumstance may be unable to declare their true identity or may be living under an assumed identity. The following are considered acceptable samples from an unidentified living person:
(a) Buccal swab
(b) Blood card or whole blood
Types of cases accepted for testing:
(b) Sexual Assault
(c) Sexual Assault: Criminal Paternity
(d) Aggravated Assault
(f) Property Crimes
Types of samples accepted for biological screening:
(a) Possible blood stains
(b) Possible semen stains
(c) Sexual assault kits
Types of samples accepted for DNA analysis:
(a) Biological stains of unknown origin
(b) Sexual assault kits
(c) Fetal material/products of conception
(d) Epithelial contact samples (accepted on a limited basis)
(e) Probative hair samples
The laboratory works with the investigating agency to determine which samples are most suitable for testing. Selection criteria will focus on the items of most probative value to the case and the items that are most likely to yield high quality, interpretable DNA profiles.
The laboratory has the right to limit the number of samples processed for each case. Limits on the number of samples processed are intended to extend laboratory funding and resources to as many cases as possible. As a general rule, a maximum of 10 samples will be processed for homicide cases; a maximum of 5 samples will be processed for sexual assault, aggravated assault, or robbery cases; and a maximum of 2 samples will be processed for property crime cases. Exceptions can be made on a case by case basis. Depending on the amount and nature of the evidence submitted, the laboratory may process fewer than the allowed maximum number of evidentiary items.
Processing of epithelial contact samples (samples with possible skin cells) is limited and determined on a case by case basis. In general, only weapons or items used to commit the crime and potential personal belongings of the assailant that were recovered from the crime scene will be considered.
Due to limited storage and screening space, bulk items such as sheets, comforters, bedding and other extremely large items are not accepted by the laboratory; cuttings or swabs of suspected stains or biological fluids from these items may be submitted.
Processing of human hair samples for mitochondrial DNA analysis is limited and determined on a case by case basis. Due to the ubiquitous nature of hair and the expense and difficulty of mitochondrial DNA testing, the probative value and significance of an evidentiary hair must be well established for testing approval. The hair must be examined by a qualified hair examiner to determine: the hair is of human origin; the hair is foreign to the known victim standard or other applicable known standards; and the presence/absence of cellular root material. This report must accompany the hair submission. In general, a maximum of 5 hairs will be processed for mitochondrial DNA analysis.
DNA Associations to date
Designated as the state’s missing person laboratory since 2002
Accredited ISO 17025 since 2004
Designated as a criminal justice agency since 2011