FBI analysis on alleged Romero hair excluded from trial

Superior Court Associate Judge Joseph N. Camacho has granted a motion to exclude the mitochondrial DNA test results and testimony of a Federal Bureau of Investigation forensic examiner on a strand of hair recovered from a car that was allegedly driven by murder suspect Joseph A. Crisostomo.
In granting Crisostomo’s motion, Camacho excluded FBI forensic examiner Lara Adams’ test results and conclusion that murdered bartender Emerita Romero cannot be excluded as the source of the unknown mitochondrial DNA sample. Camacho also denied the Commonwealth’s motion to certify Adams as an expert to testify about this mitochondrial DNA test results.

The judge, however, denied Crisostomo’s motion to exclude the mitochondrial DNA test results and Adams’ expert testimony that Crisostomo can be excluded as the source of the unknown mitochondrial DNA sample. Camacho also granted the Commonwealth’s motion to certify Adams as an expert qualified to testify about this.

“In sum, the court finds that the data underlying the statistical analysis is not sufficient to provide reliable information to the jury,” Camacho said.

The Commonwealth asserts that Romero was in a car driven by Crisostomo on the night she died. The government recovered a hair from that car, and asked the FBI to compare the mitochondrial DNA from that hair sample to known samples of Romero and Crisostomo.

FBI forensic examiner Adams performed the analysis. She concluded in her report that Crisostomo could be excluded as the source of the hair but not Romero.

Crisostomo, through counsel Janet H. King, asked the court to exclude Adams’ testimony and the results of the mitochondrial DNA analysis she did.

King argued that due to the limitations of the FBI’s mitochondrial DNA database (“CODIS”), the statistical analysis provided is not reliable in this case, and therefore the mitochondrial DNA results should be excluded under the Commonwealth Rules of Evidence.

The Commonwealth argued that the statistical analysis should not bear on the admissibility of the evidence.

The government argued that it is only the results of the mitochondrial DNA comparison, whether or not the known sample matches the unknown, that should be considered under the Rules and the statistical analysis merely goes to the weight of the conclusion, not its reliability.

The court held a hearing on the issues last Feb. 18 and 21.

In his order on Friday, Camacho explained that mitochondrial DNA sequencing analysis involves genetics, chemistry, molecular biology, and statistics.

Camacho said human cells contain two types of DNA: nuclear DNA, two copies of which are found within the nucleus of each cell, and mitochondrial DNA, found in the mitochondria. Each cell has thousands of mitochondria, and thousands of copies of mitochondria DNA.

Mitochondrial DNA is inherited from only the mother, and is shared between relatives who have the same maternal lineage. This means that mitochondrial DNA is not a unique identifier. A person has the same mitochondrial DNA as his or her mother, mother’s mother, siblings who share a mother, and so on.

Additionally, sometimes unrelated people have identical mitochondrial DNA.

A mitochondrial DNA sequencing analysis involves comparing the mitochondrial DNA of two samples, and if the base sequence in the mitochondrial DNA samples match, searching a mitochondrial DNA database to determine how common or uncommon that particular mitochondrial DNA sequence is.

If the samples contain different base sequences, then the person who provided the known sample can be excluded as the source of the unknown sample.

When the samples are distinct, the analysis ends at this point, as the ability to exclude the person who provided the known sample is meaningful without statistical analysis.

However, if the samples contain the same sequence, then the base sequence found in the samples is compared against a database of mitochondrial DNA to determine how rare or common that particular sequence is.

The frequency of the mitochondrial DNA sequence in the population gives meaning to the conclusion that the known source cannot be excluded as the source of the unknown sample.

The FBI’s mitochondrial DNA database, CODIS, is composed of 4,000 mitochondrial DNA samples from 4,000 individuals. Adams testified that in the vast majority of cases, the CODIS database is sufficient.

However, she stated that this particular case has been the source of much discussion at the FBI and is likely to prompt a change in standard operating protocol.

Several ethnic groups present in the CNMI, and therefore relevant in understanding the frequency of a mitochondrial DNA sequence found in the CNMI, are not included in the CODIS database.

CODIS includes samples from individuals who identify themselves as Chinese, Korean, Japanese, and Caucasian, so the FBI report includes upper bound frequency estimates for those groups.

However, CODIS does not contain profiles from individuals from the Philippines, or Chamorro or Carolinian descent, or any other Micronesian population groups.

Thus, Camacho said, the FBI report provides no information about the frequency of the mitochondrial DNA sequence among these groups.

Camacho said that based on a review of the filings, the testimony and exhibits presented during the hearing, and the applicable law, the court finds that the statistical analysis provided in this case is not reliable and does not meet the standards of Rules of Evidence.

The judge noted that the CODIS database does not include several of the major ethnic groups of the CNMI, such as Filipinos, Chamorros, Carolinians, or any other Micronesian population group.

Camacho said Adams’ explanation of the problems with providing upper bound frequency estimates based on only one ethnic population group, or the combination of multiple population groups, indicates that the lack of a representative database results in the absence of useful information for the jury.

Crisostomo faces charges of kidnapping and killing Romero, whose body was found in the former La Fiesta Mall in San Roque on Feb. 7, 2012. The jury trial will start on April 7, 2014.