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New York City Agency Has Underreported Lab Errors In DNA Database It Oversees

At least one error led to a wrongful arrest, according to a Freedom of Information Law request, underscoring the need for better oversight of the Office of Chief Medical Examiner, advocates say.

A lab worker prepares liquids at the Office of Chief Medical Examiner on September 6, 2018 in New York.
ANGELA WEISS/AFP via Getty Images.

New York City Agency Has Underreported Lab Errors In DNA Database It Oversees

At least one error led to a wrongful arrest, according to a Freedom of Information Law request, underscoring the need for better oversight of the Office of Chief Medical Examiner, advocates say.


The New York City Office of Chief Medical Examiner, which maintains a controversial police DNA database that contains tens of thousands of samples, has underreported laboratory errors and other mistakes that it is required to disclose under city regulations. 

According to a recent Freedom of Information Law request filed by the Legal Aid Society and shared with The Appeal, the OCME disclosed errors that led to a wrongful arrest in a rape case and disclosed that it had created DNA profiles using contaminated samples.

Since 2014, the OCME has been required by city law to conduct a “root cause analysis” whenever significant errors or mistakes occur that affect the reliability of the office’s evidence examination and analysis. But Terri Rosenblatt, the Legal Aid staff attorney who runs the organization’s DNA unit, said nearly half of the 15 error disclosures were caught by defense attorneys, not by the lab.

“Errors like these, and the lab’s inability to detect them, should concern the public” because they undermine confidence in the criminal legal system, Rosenblatt said in an interview. “More and more often, criminal cases rise and fall on DNA evidence.”

Aja Worthy-Davis, a spokesperson for the OCME, said lab errors that “warrant report under City law equated to less than one-hundreth of 1 percent” of cases in the last five years. “Although our error rate is minimal, we use rigorous quality control within laboratories to ensure we are operating with the utmost integrity and accuracy,” she said in an email to The Appeal.

OCME is fully transparent about errors and mistakes in its laboratories, and is fully committed to that transparency,” Worthy-Davis added.

Legal Aid said the current OCME regulations allow the agency too much leeway in determining whether errors should be disclosed. Under the regulations, the office must tell the mayor and City Council when it discovers at least one of the following occurred: intentional analyst misconduct that leads to fabricated results, significant errors affecting the accuracy of its report, failures to follow protocols affecting the accuracy of the report, and false or misleading statements in testimony by laboratory employees.

The FOIL disclosures come ahead of a City Council oversight hearing scheduled for Tuesday, where the Legal Aid Society says it plans to lay out a litany of missteps by the OCME that will show its laboratory needs tougher regulations.


Among the new error disclosures is a mistake that led to a 2016 wrongful arrest. A laboratory analyst incorrectly entered data into state and national database, resulting in the arrest of a man for an alleged rape for which he had an alibi: He had been in prison at the time of the alleged crime.

In another example, a homicide victim’s DNA was wrongfully uploaded into the OCME’s database because of contamination; two decedents were autopsied in 2017 on the same day in the same mortuary. The Manhattan district attorney’s office had to inform the OCME that the sample did not match the suspected perpetrator in the case, according to a letter explaining the error.

“If the lab is making mistakes like these, who is to say that they couldn’t wrongly point the finger at one of these individuals, leading to a potential wrongful prosecution,” Rosenblatt said.

The Legal Aid Society said it requested the OCME’s root cause disclosures, after the New York Daily News reported in October that a polluted DNA sample, uploaded to its database, resulted in a wrongful arrest. An NYPD detective arrested and questioned Darrell Harris about a Dec. 19, 2018, home burglary in South Jamaica, Queens, after police said his DNA had been recovered from the window of the home. Upon further investigation, the OCME informed police that the window sample had been handled, and contaminated, by a lab technician who hours earlier handled a voluntary DNA sample Harris gave to the NYPD related to a separate sexual misconduct allegation. Harris also provided an alibi which placed him in New Jersey at the time of the burglary.

The OCME later removed the DNA sample from its database “out of extreme caution,” according to the Daily News. The Queens district attorney’s office dropped burglary charges against Harris on June 28, after he had spent $25,000 on a lawyer and lost his job working on the tarmac of the John F. Kennedy airport.


The OCME maintains a local index system of at least 83,004 forensic DNA profiles, which are created from evidence taken from a crime scene, according to a Jan. 10 letter from the office. Separately, as of January, there were over 32,158 suspect samples. That’s an increase of well over 19,000 profiles since July 2017, when the office was storing about 64,000 profiles, according to WNYC.

A Legal Aid analysis found that the OCME added more than 700 profiles from people suspected of crimes to its DNA index since August, but only 281 evidence profiles for the same time period.

The Appeal previously reported that the OCME had removed 372 profiles from the database over the last five years when it discovered the associated DNA samples matched case victims or witnesses. The office is prohibited from permanently maintaining profiles of people who have not been convicted of a crime.

On Thursday, the NYPD, which collects the DNA stored by the OCME, announced that it would begin conducting an audit of about 32,000 samples from people suspected of committing a crime. The department also said it would make the process to remove a profile from the database easier and would impose limits on the collection of samples from children, the Wall Street Journal reported. (Despite a 2018 state court ruling that bars police from collecting samples without the consent of a parent or legal guardian, the OCME continues to accept DNA samples collected surreptitiously from minors.)

“These changes are common sense and incorporate feedback we have gathered without compromising the ability for officers to successfully identify criminals, build strong cases and bring justice for victims,” said NYPD Commissioner Dermot Shea, according to a New York Times article.

Rosenblatt said the OCME should not go another day without stricter regulations and oversight.

“We hope that the council will insist on much greater transparency about the collection and storage that has already happened, and order the OCME and NYPD to end their unethical and unlawful DNA tactics right away,” Rosenblatt told The Appeal.