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1 Using DNA and CODIS to Resolve Missing and Unidentified Person Cases B.J. Spamer NamUs Training and Analysis Division Office: Cell: Free Online Training Click Online Training 1

2 DNA Profiles Used in MP and UP Cases Three types of profiles used in missing and unidentified person investigations: STR Profiles Short Tandem Repeats Also commonly referred to as Nuclear DNA profiles Y-STR Profiles Y-Chromosome Short Tandem Repeats Mitochondrial (mtdna) Profiles Short Tandem Repeat (STR) Profiles STR profiles (also called NUCLEAR DNA PROFILES) are passed down to a child by both the mother and father 50% from each parent. Mother Father Daughter Son 2

3 Short Tandem Repeat (STR) Profiles STR profiles (also called NUCLEAR DNA PROFILES) are passed down to a child by both the mother and father 50% from each parent. Mother Father Daughter Son Short Tandem Repeat (STR) Profiles STR profiles (also called NUCLEAR DNA PROFILES) are passed down to a child by both the mother and father 50% from each parent. Mother Father Daughter Son 3

4 Short Tandem Repeat (STR) Profiles 13 specific STR loci serve as the standard for CODIS, to ensure uniformity and the ability to share DNA information between laboratories. Advantages of STR Profiles Most discriminating of the three DNA profiles The likelihood of two individuals (except identical twins) having the same 13-loci DNA profile can be 1 in 1 billion or higher. Most comparisons between convicted offender/arrestee profiles and suspect profiles from crime scenes are performed with STR profiles 4

5 Disadvantages of STR Profiles Particularly in degraded and/or skeletal remains cases, complete or even partial STR profiles may no longer be obtainable. This may severely limit CODIS searching. Closely related family references (mother, father, sister) may not be available for missing persons the more distant a relative, the less useful their STR profile is for comparisons. For Example: Juvenile missing in the 1980 s. Skeletal remains were found in the 1990 s but were not identified as the missing juvenile. DNA was collected from one sibling and an STR profile only was uploaded to CODIS in the early 2000 s. No associations were made, despite the fact that both the MP and UP were represented in CODIS with STR profiles. When an additional family reference sample was profiled and uploaded to CODIS, the association was made. 5

6 How Does That Happen? 11, 17 12, 14 Mother Father 11, 12 11, 14 17, 12 17, 14 Daughter Son 11, 12 11, 14 17, 12 17, 14 How Does That Happen? 11, 17 12, 14 Mother Father 11, 12 11, 14 17, 12 17, 14 Daughter Son 11, 12 11, 14 17, 12 17, 14 6

7 Y-Chromosome (Y-STR) Profiles Y-STR profiles are passed only to a MALE child and only by the FATHER. Mother Father Daughter Son Y-Chromosome (Y-STR) Profiles All males sharing the same paternal lineage will share the same Y-STR profile. Missing Person 7

8 Disadvantages: Y-STR Profiles Not unique to an individual Only applicable to missing/unidentified males May not be obtainable in decomposed/skeletal remains cases Advantages: Distant paternal relatives can provide a Y-STR profile for comparison purposes when close relatives are not available for STRs and/or a maternal relative is not available for mitochondrial DNA. Mitochondrial DNA (mtdna) mtdna profiles are passed to MALE and FEMALE children, but only from the MOTHER. Mother Father Daughter Son 8

9 Mitochondrial (mtdna) Profiles All females sharing the same maternal lineage will share the same mtdna profile. All males from the same mother will also share the same mtdna profile. Missing Person The Importance of mtdna mtdna is more resilient to degradation Skeletal remains may no longer yield a full STR or Y-STR profile, but still yield a mtdna profile If we can only develop a mtdna profile for skeletal remains and there is no mtdna profile available for the missing person, we can never make an association between the two cases 9

10 Mitochondrial (mtdna) Profiles Disadvantages: Not unique to an individual associations will not report out of CODIS unless they meet a certain probability threshold. Advantages: More resilient to degradation. Distant maternal relatives can provide a mtdna profile for comparison purposes when close relates are not available for STRs and/or Y- STRs are not applicable. CODIS Mito Laboratories MN Bureau of Criminal Apprehension Connecticut State Police Lab New York Office of the Chief ME California Dept of Justice Arizona Dept. of Public Safety New Jersey State Police Lab FBI Virginia Dept. of Forensic Sciences UNT Center for Human ID 10

11 From Whom To Collect DNA Samples You must collect AT LEAST TWO family reference samples for proper CODIS searching to take place: Mother Father Offspring of Missing Person Collect second parent to exclude their STR profile Full Sibling Half Sibling Consider grandparents, aunts, uncles, etc. for Y- STRs and mtdna profiles if closer blood relatives are not available Family Reference Collection Kits Kits can be ordered through the NamUs DNA screen or from:

12 Family Reference Collection Kits Chain of custody form Consent form Donor Relationship Fax Back form Latex gloves Buccal swab collectors Return envelope These materials ensure proper documentation, collection, and chain of custody on each collected sample Direct References Direct reference samples for the Missing Person will have added value in CODIS searches: Blood/tissue samples from prior medical procedures Toothbrush used prior to disappearance Guthrie cards (also known as PKU cards) Articles of unlaundered clothing worn prior to disappearance Baby teeth Only if parent is certain tooth belongs to MP and not a sibling These samples may not yield profiles due to open root Do NOT collect cut hair unless no other mtdna donor exists cut hair will yield only a mtdna profile 12

13 DNA Index System Terminology CODIS CODIS is an acronym that stands for Combined DNA Index System. CODIS is the software that compares DNA profiles and is the backbone of the DNA Index System. Index : CODIS is a system of pointers, which point back to the originating agency; the system does not contain names or other case-related information, only the information necessary to make associations and notify agencies:» Specimen identifier» Laboratory s identifier» The actual DNA characteristics (profiles) DNA Index System Three Levels to the DNA Index System: National DNA Index System (NDIS) State DNA Index System (SDIS) Local DNA Index System (LDIS) NDIS FBI SDIS Texas Dept. of Public Safety Headquarters Laboratory LDIS UNT Center for Human Identification 13

14 DNA Index System NDIS SDIS Ohio Bureau of Criminal Investigation SDIS California DOJ - Richmond Jan Bashinski DNA Lab LDIS Miami Valley Regional Crime Lab LDIS Cuyahoga County Coroner s Office LDIS Los Angeles Regional Crime Lab LDIS San Bernardino County S.O. Degraded Samples Degraded DNA Samples (e.g., Low Copy Number) Samples may be degraded to the point where traditional techniques do not yield a DNA profile Low Copy Number (LCN) samples can be amplified a greater number of times to produce an STR profile where none could be obtained before Profiles developed using these techniques are not yet accepted into the National DNA Index System (NDIS) - only into the local and state systems, meaning NATIONAL searches will not take place 14

15 DNA Index System LCN STR Profile for UP X SDIS Texas Dept. of Public Safety Headquarters Laboratory NDIS STR Profile for MP SDIS California DOJ - Richmond Jan Bashinski DNA Lab LDIS UNT Center for Human Identification LDIS Dallas Police Department LDIS Los Angeles Regional Crime Lab LDIS San Bernardino County S.O. Partial STR profiles ARE searched at the national level of CODIS (NDIS) HOWEVER: Degraded Samples CODIS hits are dependent upon statistical probabilities of an association, so even if your partial profile is being searched at NDIS, you may not receive a CODIS hit. 15

16 The NamUs DNA Screen Complete mitochondrial DNA profile uploaded to NDIS along with marginal STR profile (4/13). Nearly complete LOW COPY STR profile (10/13) available at UNT for comparison. DNA Index System Most Commonly Used Indexes Within Each Level of CODIS: Convicted Offender Index Arrestee Index Forensic Unknown Index Missing Person Index Family Reference Index Unidentified Human Index NDIS SDIS LDIS 16

17 Family Reference Samples Reference samples provided by family members of missing persons can only be searched against the unidentified human index. Missing Person Index Family Reference Index X X X Convicted Offender Index Arrestee Index Forensic Index Unidentified Human Index Direct Reference Samples Direct reference samples for missing persons are entered into the Missing Person Index and can be searched against ALL other indexes (unidentified humans, offender profiles, and forensic unknown profiles). Missing Person Index Family Reference Index Convicted Offender Index Arrestee Index Forensic Index Unidentified Human Index 17

18 Take-Home Points Collect DNA samples from two or more family members of each missing person. The more closely related the donor, the more useful the STR profiles will be for comparisons. Make sure profiles are developed using two or more DNA technologies for every missing person case (STR + mtdna) Know when your cases have incomplete profiles to be cognizant of NDIS search issues and to know when a potential match from an investigative lead might require a manual DNA comparison. Direct references enable more comprehensive CODIS searching against offender and suspect profiles. DNA Statistics From NamUs Missing Person Cases: Complete and Uploaded to CODIS: 4,973 DNA Submitted, Pending Completion: 599 DNA Available, Not Yet Submitted: 366 Unidentified Person Cases: Complete and Uploaded to CODIS: 4,426 DNA Submitted, Pending Completion: 706 DNA Available, Not Yet Submitted: 682 No profile obtained:

19 Why Be Proactive? Missing person last seen in the 1990 s Removed from NCIC shortly after initial disappearance DNA collected from family and uploaded to CODIS after the NCIC entry was cancelled because subject was still missing law enforcement declined to make a new NCIC entry No DNA associations were made No NamUs entry was made Why Be Proactive? Unidentified remains were found in the same state where the missing person was last seen, in the same year the subject was last seen date of last contact for MP was incorrect in NCIC. No NCIC entry was made on the UP case NamUs entry was made in the late 2000 s but no DNA was processed NamUs entry prompted tip that led to DNA processing and identification over 10 years after the body had been recovered 19

20 Contact Information B.J. Spamer Director, Training and Analysis Division UNT Health Science Center Office: BJ.Spamer@unthsc.edu