Convictions May Be Jeopardized : DEA Chemist Resigns in Evidence Tampering Case

A veteran Drug Enforcement Administration chemist has resigned after allegedly admitting that she tampered with cocaine evidence in several cases that could jeopardize narcotics convictions in California, Nevada, Oregon and Washington, federal sources said Tuesday.

The chemist, Esther J. Allen, 56, admitted removing high-purity cocaine from 13 court exhibits and replacing it with another substance of equivalent weight, said the sources, who declined to be identified. They said they feared that the impact could be much wider, tainting “more than several dozen cases.”

The alleged involvement of Allen, a 15-year DEA chemist assigned to the agency’s Western Laboratory in San Francisco, came to light after U.S. District Judge Howard D. McKibben in Las Vegas agreed to postpone a cocaine-trafficking case, which was to go to trial Monday. Allen had been scheduled to testify.

Personal Use Alleged

Although authorities have not yet determined what became of the missing cocaine, one source said investigators believe that Allen used, rather than sold, what she allegedly removed from samples.

Thomas R. Green, chief of the federal organized-crime drug task force in Las Vegas, said in court papers that Allen, whom he referred to only as a DEA chemist, “will be charged with criminal offenses concerning her theft of controlled substances from packages submitted for analysis.”

Other sources confirmed that Allen was that chemist and said she resigned Monday after being interrogated by the DEA’s office of professional responsibility and the Justice Department’s public integrity section in Washington. Allen could not be reached for comment Tuesday.

Green said that the chemist’s tampering with evidence could affect a dozen drug cases in Las Vegas, including the seizure last year of 187 pounds of cocaine, described as the largest seizure in Nevada. A number of defendants have been convicted in that case, but the major ringleader is yet to be tried.

Green said that Allen had submitted a 26-page written confession, detailing methods of removing quantities of cocaine submitted to the laboratory for analysis and steps used to avoid detection.

Replaced With Manitol

After analyzing a submitted sample to determine the quantity of cocaine present, the chemist said she would remove a quantity of cocaine for her own use and replace it with Manitol, a substance used to bring the sample back to its original weight.

“Nobody but a chemist would know,” one source said, declining to disclose how investigators learned of Allen’s alleged tampering.

Green, in seeking the postponement of the cocaine trafficking case involving five defendants, said the kilogram of cocaine in the case had been diluted from its original level of purity. The cocaine will be re-analyzed and results reported to defense lawyers.

One source emphasized the difficulty of determining cases in which Allen’s chemical analysis and testimony may have tainted the prosecution. This source said only cases tried after 1981 would be affected.

No criminal charges are likely before work is completed.