Return To Court TV Homepage  
>>>>>>
TRIALS
ABOUT COURT TV

U.S.

Trials

World

People

On Air

Video

Talk

Search







    



State's DNA expert evaluates the Sheppard estate's report

Armed Forces DNA
Identification Laboratory
1413 Research Boulevard
Building 101
Rockville, MD 20850

Dean Boland
Assistant Prosecuting Attorney
Cuyahoga County Prosecutor's Office
1200 Ontario Street
Cleveland, OH 44113
Dear Mr. Boland,

I have completed my review of the case file and final consultation reports (two reports dated 3 February 1997 and 21 April 1999), which I received from the Indianapolis-Marion County Forensic Services Agency (herein referred to as FSA) regarding the Sam Sheppard case. The following, is a list of findings compiled during, my review:

1. In general, I was unable to read the DQAI and PM typing, strips provided to me, as the photocopies were of poor quality. Nevertheless, I attempted to evaluate the interpretation of the FSA's results using, the information I had available to me (e.g., some of the photocopies of typing strips were of good enough quality to read, and the majority of typing results were documented in hand written notes).

2. The only apparent oversight regarding the reporting of results is for item A-59-1. Given the mixture observed, the FSA cannot discount the possibility of a 1.2 DQAI allele.

3. Assuming that the typing, strips accurately reflect the reported results, the conclusions drawn by the FSA, specifically in their two consultation reports, are accurate at face value; i.e., Richard Eberling- could not be excluded as one of the donors of the DNA typing, results obtained from specific items of evidence (i.e., stain from Marilyn Sheppard's bed sheet, and items A-59-1, A59-2, b-3-b-1, and 1-C). However, a "failure to exclude" could mean anything- without some means to convey the weight of the typing results. The FSA does not provide a statistical interpretation of their results in order to assess the weight, or meaning of their conclusions. This must be done by the FSA at trial if their results and conclusions are to be entered into evidence. Otherwise the conclusions may be prejudicial to the triers of fact.

4. The DQAL and PM profiles reported by the FSA for specific items of evidence (i.e., stain from Marilyn Sheppard's bed sheet, and items A-59-1, A59-2, b-3-b-1, 3, and 1-C) are mixtures of more than one individual. In fact, some of the items are a mixture of three or more individuals. For example, the DQAI/PM profile of item A-59-1 (sperm fraction of a vaginal smear from Marilyn Sheppard), has six (6) possible DQAI alleles (i.e., each numerical designation indicates the presence of another "form" or allele of DQA1, where each allele is a different DNA sequence). An individual can only have two (2) DQAI alleles, thus, there are at least three individuals represented in this sample. If one were to assess the weight, or meaning of the fact that Richard Eberling- could not be excluded as a donor of DNA to this mixture, one could assess how many individuals in the general population could have contributed an allele to the mixture. However, the statistical methods to make this assessment can be somewhat complex. On the other hand, one could deter-mine how many individuals in the population could not have contributed DNA to the mixture by simply determining the percentage of the population that has alleles not represented in the mixture. The following is an example of this approach for item A-59-1:

 

DQA1

LDLR

GYPA

HBGC

D7S8

GC

Frequency

Possible Alleles

1.1, 1.2, 1.3. 2, 3, 4.1, 4.2/4.3

AB

AB

ABC

AB

ABC

African Americans (AA) = PD of 0.922* Caucasians (C) PD Of 0.937*

Alleles Observed for Item A-59-1

1.1, 1.2, 1.3, 2, 3, 4.1

AB

AB

ABC

AB

ABC

Percentage of the AA Population = 91.7%

Percentage of the C Population = 97.2%

Missing Alleles for Item A-59-1

4.2/4.3

None

None

None

None

None

Percentage of the AA Population = 8.3%

Percentage of the C Population = 2.8%

*PD= the Power of Discrimination for each Population

The information provided in the above table illustrates that the DQAI profile reported for item A-59-1 could be shared by 91.7% of the African American population, or 97.2% of the Caucasian population. Even more compelling is that only 8.3% of the African American or 2.8% of the Caucasian population could be excluded as a possible donor of the mixture in item A-59-1, and that 100% of both populations can be expected to share the same PM profile. Thus, while Richard Eberling, cannot be excluded as a donor, which may in fact be consistent with other circumstantial evidence, the DNA results provide little additional information to support the hypothesis that he was a contributor.

  1. Using, the same approach applied to item A-59-1, the following is a table listing the percentage of the African American and Caucasian populations that can be excluded as possible donors of the DNA in the respective mixtures:

Item of Evidence

Percentage of African American Population Excluded

Percentage of Caucasian Population Excluded

Stain from M. Sheppard’s Bed Sheet

Using DQA1 = 0%

Using PM = 33.3%

Thus, ~66% Cannot Be Excluded

Using DQA1 = 0%

Using PM = 1.3%

Thus, ~98% Cannot Be Excluded

A-59-2

Using DQA1 = 26.6%

Using PM = 0%

Thus, ~73% Cannot be Excluded

Using DQA1 = 25.9%

Using PM = 1.3%

Thus, ~74% Cannot be Excluded

b-3-b-1

Using DQA1 = 26.6%

Using PM = 0%

Thus, ~73% Cannot be Excluded

Using DQA1 = 25.9%

Using PM = 1.3%

Thus, ~74% Cannot be Excluded

3

Using DQA1 = 14.1%

Using PM = 0%

Thus, ~85% Cannot be Excluded

Using DQA1 = 10.1%

Using PM = 0%

Thus, ~89% Cannot be Excluded

1-C

Using DQA1 = 30.3%

Using PM = 33.3%

Thus, ~66% Cannot be Excluded

Using DQA1 = 36.5%

Using PM = 1.3%

Thus, ~63% Cannot be Excluded

 

 

Again, while Richard Eberling, cannot be excluded as a donor in each of these items of evidence, the individual results provide little additional information to support the hypothesis that he was a contributor. However, the fact that Richard Eberling cannot be excluded from any of the mixtures cannot be discounted.

6. Of interest, while the DQA1/PM profile from the pulled head hairs from Marilyn Sheppard show the 4.1 allele (the one identified in all other mixtures, and consistent with Richard Eberling), Richard Eberling can be excluded as a source of the sample at the GC locus (i.e., there is no A allele at the GC locus). This illustrates that a mixture was obtained in this case with the 4.1 allele that excluded Mr. Eberling, and suggests that the investigators should be cautious when focusing, on the 4.1 allele in all other mixtures during their assessment of the results (as was done in the case notes included in the case file).

7. Of interest, while the case notes provided by the FSA suggest that the 4.1 allele for item A-59-2 is the most intense DQAL allele in the mixture (consistent with Richard Eberling's profile), it appears from the typing, strips used to make this observation (i.e., data from 12-8-96) that the C allele for the GC locus is the most intense allele. The C allele is not present in Richard Eberling's profile, so any suggestion that the intensity of the 4.1 allele means that Richard Eberling is the major contributor is unwarranted. In fact, one could argue that the contradictory nature of these results may suggest that he is not a contributor of the profile. Nevertheless, in general, this type of assessment must be made carefully for each sample, and made with all data available.

8. It would be useful to know what validation studies were conducted to allow the FSA to perform re-amplification of certain DQAI and PM reactions. Proper studies are required to ensure the reliability of the results. Of greatest concern is that the positive control contains both a 1.1 and 4.1 DQAL allele, which could be a source of contamination during reamplification. In defense of the FSA, it does appear that negative controls were clean throughout the testing process.

Final Recommendations:

a. Any remaining evidence or DNA extracts should be subjected to short tandem repeat (STR) analysis, which is better than DQAI and PM for resolving the composition of mixed DNA profiles.

b. Any future testing (e.g., paternity testing on the unborn fetus) should be performed using STR analysis.

 

If you have additional questions or concerns please feel free to call me at 301-319-0219 or at email address.

 

Sincerely,

Mitchell M. Holland, PhD

Scientific Laboratory Director

AFDIL

   

Court TV Homepage

Site Map


<<<back Top of page  
Contact Us U.S. |  TRIALS |  WORLD |  PEOPLE |  ON AIR |  VIDEO |  TALK |  ABOUT CTV |  SEARCH 
      © 2000 Courtroom Television Network LLC. All Rights Reserved.
Terms & Privacy Guidelines