One day last December, a Brooklyn prosecutor called the Police Department laboratory to check on a test of drugs that had been seized six weeks earlier.
The drugs were nowhere to be found in the laboratory.
As officials hunted for the evidence in that case, they made a startling discovery: The drugs seized in 42 other arrests made in Brooklyn that same day, Oct. 20, 2006, also had vanished without a trace.
In short, all the evidence from every narcotics arrest in Brooklyn that day was gone.
“A search was conducted, disclosing that an entire bundle of narcotics, 43 in total, which should have been submitted to the laboratory for examination was not present,” Dr. Peter Pizzola, the director of the laboratory, wrote in a letter in April to an organization that oversees forensic laboratories. “Additionally, all paperwork associated with this delivery was also missing.”
Despite an inquiry that began over a year ago, officials still cannot say whether the drugs were lost, stolen or thrown away. Investigators believe that a police officer serving as a courier took several large plastic bags of drugs as far as the laboratory. There, the trail goes cold.
At various stages, prosecutors from all five boroughs have joined the Police Department’s Internal Affairs Bureau in the investigation, which is now being led by the district attorney’s office in Queens, because the laboratory is there.
“This remains an active investigation,” John M. Ryan, the chief assistant district attorney in Queens, said on Tuesday.
The drugs were seized in both felony and misdemeanor arrests, at least some made by police officers working undercover.
Authorities in Brooklyn said on Tuesday that they could not immediately determine what had become of those 43 cases, but that without the evidence — much less the laboratory analyses, which were not performed— it was unlikely that any prosecutions could have taken place.
Scientists in the lab measure the weight and purity of the drugs, factors that determine the severity of the charges and penalties.
“We are reviewing the records, but we would expect that it would difficult to proceed without the evidence, and in a timely manner,” said Jerry Schmetterer, a spokesman for the Brooklyn district attorney, Charles J. Hynes.
The Police Department has not publicly disclosed the mass loss of drugs last year. However, the missing evidence was mentioned in a footnote on page 32 of a report issued last week by the state inspector general, Kristine Hamann, that dealt with charges of a cover-up of serious misconduct in the laboratory five years ago.
Ms. Hamann noted that new managers at the laboratory had promptly notified city prosecutors and a professional oversight group about the disappearance of the drugs. A police spokesman took questions on Tuesday about the episode, but did not provide any information.
For generations, the investigation of illegal narcotics trafficking — and the subsequent handling of evidence — has been a fraught subject for the Police Department, exposing the honest to the perils of contact with violent people, and the corrupt to the temptations of easy money.
Perhaps the most notorious episode involved the theft of 120 pounds of cocaine and 398 pounds of heroin from the police property clerk’s office, a portion of which had been seized in the case that was made famous in “The French Connection,” the 1971 movie.
Years later, the police discovered that on six occasions from 1969 to 1972, someone had used a version of a detective’s name and badge number to check the drugs out of storage. The bags that took their place contained a mixture of flour and cornstarch. The theft was discovered when swarms of red beetles ate through the bags.
Though the amount of the drugs that disappeared last year is not known, officials said none of the cases that day involved big seizures, and certainly nothing approaching the scale of the French Connection case. And those who have been involved in the investigation say that honest error — rather than theft — could provide the most reasonable explanation.
At least once a day, police couriers travel to every precinct to collect sealed evidence bags that contain suspected narcotics. As the evidence is handed from one officer to the next, the chain of custody is documented in evidence vouchers.
Then the evidence bags are bundled into larger bags — similar to plastic garbage bags — and taken by the courier to the laboratory, generally late at night. There, the bags are logged by officers and stored in the Evidence Control Section until the contents are removed for analysis.
This was the procedure that should have been followed on Oct. 20, 2006, when one officer arrived with all the apparent narcotics seized in Brooklyn.
“The messenger had no receipt proving that the evidence had been submitted to the laboratory,” Dr. Pizzola wrote in his April 27 letter, which was addressed to Ralph Keaton, the executive director of the American Society of Crime Laboratory Directors/ Laboratory Accreditation Board. The text was read to The New York Times by a law enforcement official involved in the inquiry.
DESPITE the lack of paperwork, officials say that they are virtually certain that the police messenger did take several large bags of evidence to the laboratory. It is not clear how this was established; the officials, who spoke on the condition that they not be identified because of the continuing investigation, would not say if the laboratory has video recordings of those who come and go.
What happened next remains a mystery. There is no record that the drugs, including what seemed to be marijuana, cocaine and heroin, collected on Oct. 20, 2006, were ever logged into the Evidence Control Section. It appears certain that they never were checked out by any of the 100 scientists in the lab.
In his letter, Dr. Pizzola said he had been told by investigators with the department’s Internal Affairs Bureau that, “In their opinion, the laboratory’s Evidence Control Section was responsible for the loss of 43 cases of narcotic evidence.”
He summed up the episode with a question: “Was it a criminal act by a member of the laboratory, or an accidental loss of the evidence by mistaking the bundle as trash, or another error?”