By Robert Phillips, Deputy District Attorney (Ret).

Use of a Sexual Assault Victim’s Rape Kit DNA in a Later Prosecution of that Same Victim 

The San Francisco’s District Attorney Chesa Boudin recently announced (as reported in the San Francisco Chronical) that he was dropping “felony property charges” previously filed against a woman in a case submitted by the San Francisco Police Department.  The stated reason for the dismissal is that she was apparently identified and charged solely through the use of her own DNA which she herself, as a sexual assault victim, had previously provided by submitting to a “rape kit” examination.  (No further details were provided out of respect for her privacy.)  

DA Boudin stated that he was disturbed to learn that using rape kit DNA to later identify and charge women in unrelated criminal cases is “a routine practice not only in San Francisco but at other crime labs across the state.”  Referring to this practice as “unlawful,” and “legally and ethically wrong,” the DA vowed not to allow the practice in San Francisco’s courts.  But is such a practice “illegal,” as DA Boudin stated?  It may very well be an “ethical” violation.  (I’ll leave that issue to the ethics police.)  And it’s certainly arguable, as DA Boudin pointed out, that this practice might very well discourage sexual assault victims from coming forth and reporting their crimes if they knew that their DNA would be included in a database that could later be used against them.  But a quick review of the relevant case law tends to indicate that DA Boudin is simply wrong in claiming that the practice is “illegal.” 

As noted by San Francisco Police Chief Bill Scott, his department’s “existing DNA collection policies have been legally vetted and conform with state and national forensic standards.”  And while there is as of yet nothing directly on point (statutorily or by case law) with the DNA collection and use practice at issue here, there is abundant case law tending to indicate that the manner by which law enforcement gains access to a suspect’s DNA is generally irrelevant.  (See People v. Gallego (2010) 190 Cal.App.4th 388, 394-398: Abandoning a cigarette butt onto a public street constitutes a loss of one’s right to privacy in that butt, making it available to law enforcement to recover and test for DNA without a search warrant.  People v. Thomas (2011) 200 Cal.App.4th 338: There is no privacy right in the mouthpiece of a PAS (Preliminary Alcohol Screening) device, which was provided by the police and where defendant abandoned any expectation of privacy in the saliva he deposited on the device by failing to wipe it off.  People v. Roberts (2021) 68 Cal.App.5th 64:  Once validly obtained, DNA evidence may be used in the investigation of an unrelated murder.  People v. Robinson (2010) 47 Cal.4th 1104, 1116-1129: Mistakenly collecting blood samples for inclusion into California’s DNA data base (See Pen. Code § 296), when the defendant did not actually have a qualifying prior conviction, is not a Fourth Amendment violation. But even if it were, it does not require the suppression of the mistakenly collected blood samples, nor is it grounds to suppress the resulting match of the defendant’s DNA with that left at a crime scene.)  Even tricking a person into providing a DNA sample has, at least in other jurisdictions, been held to be lawful.  (See Commonwealth v. Perkins (Mass. 2008) 883 N.E.2nd 230; and Commonwealth v. Bly (Mass. 2007) 862 N.E.2nd 341: Testing cigarette butts and a soda can left behind after an interview with police is lawful.  Commonwealth v. Ewing (Mass 2006) 67 Mass.App.Ct. 531 [854 N.E.2nd 993, 1001]: Offering defendant cigarettes and a straw during an interrogation.  People v. LaGuerre (2006) 29 A.D.3rd 822 [815 N.Y.S.2nd 211]: Obtaining a DNA sample from a piece of chewing gum defendant voluntarily discarded during a contrived soda tasting test.  State v. Athan (Wash. 2007) 158 P.3rd 27: DNA obtained from defendant’s saliva from licking an envelope he mailed to detectives in a police ruse.) 

Therefore, at least until California’s Legislature (never having seen an anti-police measure it didn’t like) outlaws the practice of using rape kit DNA results against the woman providing it, it appears that DA Boudin was simply incorrect in describing the practice as “illegal.”