2012 08 29 NYT DNA Evidence in Police Interrogation Rooms Requires Bleach – NYTimes.com
Before Lifting DNA, Meticulous Protocol
It is a small bit of trickery masquerading as generosity: A suspect is offered a cigarette or a soft drink in a police interrogation room.
The ruse is a staple of television crime dramas. Detective so-and-so asks questions; the suspect does not cooperate, but unwittingly leaves damning DNA on a cigarette butt or a soda can. Cue the handcuffs. Roll the credits.
But in the detective squad rooms of New York City, the procedure is far from that simple.
Consider Section 4(a), which tells interrogators that when “providing a partially consumable object that is prepackaged by the manufacturer with other objects in a ‘pack’ type container (e.g. cigarettes, chewing gum), provide an unopened ‘pack’ type container to the suspect.”
Or Section 2(b), which calls for cleaning surfaces in reach of the suspect with a “solution consisting of a 10-to-1 ratio of water to bleach” and then drying those surfaces.
The protocols are listed in a Police Department memo from the chief of detectives, Phil T. Pulaski. The directive, dated June 2010, is clearly aimed at preventing contamination of potential DNA samples.
The requirements are surely not the stuff of Hollywood.
“I don’t think we’ve ever written a scene that way,” said Warren Leight, an executive producer and show runner for “Law & Order: Special Victims Unit.”
Detectives are told to do several cleaning chores before bringing a suspect into the interview room or “other area where the DNA Examplar Abandonment Suspect Sample will be collected.” In addition to cleaning with the bleach-and-water solution, detectives are told to place a “clean garbage bag into the garbage pail” and a “new, unused, clean disposable ashtray on a surface within reach of the suspect.”
Even collecting the discarded sample can be tricky. If the suspect drank from a plastic container, for example, the detective should “create a small hole in the lower portion of the bottle and allow the beverage to drain out.”
And, in a nod to chain-of-custody issues relating to evidence, detectives are somewhat improbably tasked with maintaining “unbroken eye contact” with the sample “until it is collected.”
All the rules, one detective said, have discouraged detectives from seeking DNA samples during suspect interviews. The detective noted that if they do get a DNA sample, they could be called to testify in court about whether they followed the protocol, and any admission that they did not could prove damaging to a case.
“The big hiccup is the 10 parts water to one part bleach thing,” the detective said. “Guys don’t want to go to trial and testify about that.”
“The guys are saying, ‘If it’s going to be this much trouble, forget about it,’ ” the detective said, speaking on condition of anonymity because he was not authorized to discuss police tactics.
The department’s chief spokesman, Paul J. Browne, said that there was “no evidence of a drop, precipitous or otherwise, in the collection of abandonment samples” since the new guidelines were enacted.
Mr. Browne said the memo reflected rules that have been in effect since 2008. There had previously been “problems with samples not being properly stored, or contaminated from other stuff,” Mr. Browne added, although he said he did not know the particular circumstances.
Other detectives said that scrubbing the interview room before a suspect enters is not always convenient, particularly in fast-moving cases or on busy days.
“It’s as if you have to prepare for a guest,” Michael Palladino, the head of the detectives’ union, said of the rules. “However, these are the challenges that technology presents.”
Elizabeth Joh, a law professor at the University of California, Davis, said that there were very few legislative or judicial restrictions on the collection of so-called abandoned DNA, although she has questioned the notion that DNA can properly be considered to have been abandoned.
“This investigative technique ought to be renamed ‘covert involuntary DNA sampling,’ ” she wrote in a 2006 law review article.
Nonetheless, in some cases across the country, judges have found that people have no expectation of privacy regarding cigarette butts or soda cans — or testing of the genetic material on them — when they leave them behind as trash.
Professor Joh said it was unclear how many DNA samples the police took surreptitiously each year, but several defense lawyers in New York said it was relatively uncommon here. Nationwide, however, the police have used the technique to make arrests in a number of cold cases.
A Queens defense lawyer, Marvyn Kornberg, said that although he had not handled a case in which a client’s abandoned DNA was at issue, he imagined that the cleanliness of an interview room could make for an interesting line of cross-examination.
“Detective,” Mr. Kornberg said, launching into an imaginary cross-examination, “Do you know if they cleaned the table? What was the last time the table was cleaned?”
Mr. Browne, the police spokesman, said he had heard anecdotally how lately some suspects were careful to refuse to take any offerings from detectives.
Their caution is understandable, given how often the technique is depicted on television. Mr. Leight, the television producer, said he had a rule against using the abandoned-DNA ruse, or any other investigative trick, more than three times per season.
“Last year we did an abandoned tissue,” Mr. Leight said, “and we did a cigarette butt from a mother in a halfway house.”
“I don’t think the cops mind repeating a technique, but it makes us look lazy,” he said.