Reevaluating the Threshold Question in the Wake of Carpenter and the Path of the Golden State Killer

• Publication year: 2019
• Author: By Brady O'Bryan*

Reevaluating the Threshold Question in the wake of Carpenter and the path of the Golden State Killer

By Brady O'Bryan*

Introduction

Between 1974 and 1986, a string of brutal rapes and murders terrorized California.¹ Though the crimes spread across ten different counties, their similarities led law enforcement to suspect that the perpetrator was a single man—"The Golden State Killer" ("GSK").² Until recently, efforts to identify the sadistic criminal had produced little more than rough sketches.³ Then, Paul Holes, a crafty investigator and DNA expert, wondered if the recent rise of commercial genealogy databases could provide the spark in a case that had run four-decades cold.⁴ As it turns out, law enforcement had long held a sample of GSK's DNA collected from a crime scene.⁵ However, because the sample did not match any profile in the government's DNA databases, it was all but useless.⁶ Until now. In a stroke of genius, Holes sent in a sample of the DNA⁷ to GEDmatch.⁸ The open-source ancestry site established a connection to GSK's great-great-great grandfather.⁹ From this point, investigators were able to craft a sprawling family tree that narrowed their search.¹⁰ That was all they needed to produce the case's biggest break in 40 years—GSK had a name.

The investigation tactic has since inspired other law enforcement offices to do their own ancestry sleuthing, and understandably so.¹¹ Until now, DNA identification was limited because law enforcement's database contained a small subset of the population—largely convicted felons.¹² Even with this limit, DNA identification is ubiquitous and a powerful tool for detectives and prosecutors bringing criminals to justice.¹³ Recent reporting indicates that the pool of profiles submitted to online genealogy services is large enough to identify sixty percent of white Americans; and that number is expected to rapidly increase in the coming years.¹⁴ It is no surprise that law enforcement wants to augment its existing database with open-source ancestry sites and someday gain the ability to identify every person in the country by DNA sample.¹⁵ It is the kind of power J. Edgar Hoover could only have dreamt of while painstakingly cataloging his fingerprint database.

One cannot be blamed for feeling a bit uneasy about such a powerful investigative tool in the hands of the government. But there may be some hope for the queasy. Just last year, in Carpenter v. United States, the Supreme Court diverted from a rigid application of long-standing Fourth Amendment doctrine to limit law enforcement's use of Cell Site Location Information—another investigative tool of immense power giving the cell-phone-reliant-public pause.¹⁶In particular, the decision challenged the subsequent reach of the third-party doctrine (the rule that Fourth Amendment protection does not extend to information voluntarily disclosed to a third party).¹⁷ However, I argue that Carpenter is more significant for the broader implication that rigid rules are simply unworkable in the digital age.

With all of this in mind and the GSK's case as the motivation, this paper examines what, if any, constitutional protection there is for one's DNA. In Part I, I look to formulate an analytical framework that encapsulates each of the disjointed Fourth Amendment search doctrines. In Part II, I will apply this framework to answer the threshold question: does requesting analysis from an open-source ancestry site constitute a search under the Fourth Amendment? I argue that it does.

Part I

I begin by attempting to reframe the test espoused in Katz v. United States, known as the "reasonable expectation of privacy".¹⁸ Since that decision, the Fourth Amendment's threshold inquiry has been framed by Justice Harlan's conception of an "objective" and "subjective" standard of reasonableness.¹⁹ However, the Court has attempted to augment the vague standard with rigid doctrines such as the "third-party doctrine"²⁰ and the "open field doctrine".²¹ Additionally, the Court recently reaffirmed the "trespassory rule," which requires no reasonableness inquiry when law enforcement has gained information as a result of a trespass to property.²²

In this part, I determine a unifying theory of the Fourth Amendment by reducing the various threshold doctrines to three inquiries of degree. The first looks to what extent the information obtained by government action has the potential to reveal the "privacies of life". The second asks how comparable the government action is to a reasonable action taken by a member of the general public. Finally, the third asks to what extent the suspect voluntarily disclosed the information to a third-party.

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First Inquiry: Nature of the Information Obtained

In Carpenter, Justice Roberts recognized that a central aim of the Fourth Amendment is to protect the "privacies of life" against arbitrary government intrusion.²³ In line with this, the first question goes to the intimacy of information obtained to ascertain whether it deserves protection from capriciousness. The Court has expressed no rigid rule to define what information should constitute the "privacies of life". However, the Fourth Amendment cases do contain important guideposts that illuminate the inquiry.

The first guidepost comes from United States v. Place, where the Court concluded that a dog sniff was not a search because the surveillance disclosed "only the presence or absence of . . . contraband".²⁴ The Court suggested that there is no reasonable expectation of privacy in evidence of criminality.²⁵ However, the Court did explain that the dog sniff stands alone as a surveillance tool that reveals only incriminating details, for now at least.²⁶ We can conclude that, when surveillance can reveal only incriminating information, there is no search. Beyond information that is purely inculpatory in the abstract, the inquiry turns on the degree of intimate detail revealed.

Consider Carpenter alongside United States v. Miller. In Carpenter, the Court considered whether continuous location tracking using Cell Site Location Information ("CSLI") was a search.²⁷ And in Miller, the information in question was bank records of discrete financial transactions.²⁸ In Carpenter, Chief Justice Roberts acknowledged the qualitative differences between tracking a suspect's location continuously, with nearly infallible precision, and obtaining discrete bank records.²⁹ No one could argue that bank transactions do not reveal intimate details. However, Roberts argued that the information revealed in bank records is "limited" in a way that CSLI was not.³⁰

One point of distinction between bank records and CSLI is the right to privacy in one's location. Location, the Court has argued, can provide a "wealth of intimate detail" including "familial, political, professional, religious, and sexual associations".³¹ Furthermore, Justice Roberts appeared particularly concerned about the retrospective quality of CSLI.³² However, many of those same privacies of life could be discerned from bank transactions as well. Thus, the question is one of degree—how expansive and encyclopedic is the window into a person's life?

In sum, the first inquiry asks: to what extent does the information obtained reveal the "privacies of life"? If the information is only evidence of crime, such as the unique scent of narcotics, then there is no search. However, in most cases, at least some non-inculpatory intimate details are at risk. If the information is discrete and limited, like bank records, Miller suggests that the Fourth Amendment provides a weaker degree of protection. On the other hand, if the information is expansive and encyclopedic, then Carpenter suggests that the Fourth Amendment interest is stronger. With an idea of how strong the privacy interest is in the information obtained, the inquiry proceeds to step two.

Second Inquiry: Nature of the Investigative Method

The second inquiry scrutinizes how the government obtained the information and asks whether the method is one that is publicly available. Based on the availability of the method, the result of the inquiry will cut against the strength of the privacy interest at step one to reduce the overall reasonableness of an expectation of privacy. The inquiry is most in line with the Court's treatment of sense enhancement technology and open fields. As exemplars of these two doctrines, the guideposts here are Kyllo v. United States and California v. Ciraolo.

As in the first inquiry, there is a dispositive question. In Jones, the Court reaffirmed the long recognized Fourth Amendment protection from surveillance requiring a physical trespass.³³ The "trespassory rule" treats any physical trespass to obtain information as a search. As with purely inculpatory information at step one, a finding of physical trespass ends the inquiry.³⁴ If not, it is again, one of degree.

The first guidepost comes from Ciraolo. In that case, the government, acting on an anonymous tip, took aerial photographs of Ciraolo's backyard where he was growing marijuana.³⁵ The Court reasoned that this was not a search because the plane flew at an altitude that was within the bounds of navigable airspace for commercial planes.³⁶ Thus, any member of the public could have observed what the aerial photographs captured.³⁷ The bright line rule from Ciraolo...