IV. THE REASONABLENESS OF INNER-DIRECTED AND OUTER-DIRECTED TRAWLING
Thus far, I have maintained that any extraction of DNA from the body of the individual in custody should be treated as a search. (179) As such, the government must justify the lack of a warrant and probable cause. As noted at the start of Part III, courts have upheld acquisition and profiling of samples along with trawling the resulting databases for inner-directed matches on two alternative theories--direct totality-of-the-circumstances balancing and the special-needs exception to the warrant requirement. The former approach repudiates decades of Fourth Amendment doctrine preventing courts from making ad hoc judgments of the reasonableness of dispensing with warrants and probable cause.
Time and again, the Supreme Court has demanded adherence to a framework of categorical exceptions to the warrant requirement. (180) The special-needs exception, therefore, is more palatable, but it takes considerable effort to conclude that a search to gather information with which to link an individual to a crime implements a government interest distinct from ordinary crime control. (181) It would be better to recognize a new exception that permits the government
to acquire, analyze, store, and trawl biometric data without a warrant and without individualized suspicion when five conditions hold: (1) the person legitimately is detained (or the data are acquired without confining the individual); (2) the process of collecting the data is not physically or mentally invasive; (3) collection proceeds according to rules that prevent arbitrary selection of individuals; (4) the biometric data are used only to establish or authenticate the true identity of a given individual or to link individuals to crime scenes; and (5) the authentication or intelligence-gathering system is valid, reliable, and effective. (182) In these circumstances, the intrusion on liberty and informational privacy interests is relatively minor, and the balance of interests that underlies the normal demand for a warrant does not apply. (183)
For present purposes, however, deciding among these three approaches is not essential. Totality balancing, special-needs balancing, and the balancing required to justify a categorical exception applicable to a DNA database all involve the same weighing of the same interests, (184) This Part demonstrates including the interests of close kin in the balance does not produce a new outcome.
The State's Interests
Governments have three principal interests in expansive DNA databases: establishing the true identity of known (or suspected) offenders; detecting the perpetrators of crime for the usual purposes (retribution, deterrence, incapacitation, and rehabilitation); and exonerating falsely convicted individuals. (185) The second interest is predominant, but the others contribute a bit more to the government's case. Several comments on these interests are in order.
Authentication: True Identity
To begin with, before the 19th century, law (and revenue) officials found it difficult to know the true identities of everyone with whom they had contact. Prisoners might escape or use an alias when arrested for other offenses. Consequently, jailers began recording identifying information such as weight, height, and fingerprints of offenders and arrestees, (186) and courts readily upheld collecting biometric data on individuals taken into custody, (187) Although it might seem as if adding DNA to the repertoire of measurements that establish identity is superfluous, (188) it can be argued "[u]nless the Fourth Amendment creates a constitutional straightjacket that fits but one biometric identifier, the narrow, 'true identity' exception should pertain to DNA genotyping as much as it does to fingerprinting." (189) Even if this is a sufficient reason to establish an offender DNA database, however, it does not overcome legitimate interests of offenders or relatives in being free from trawls for inner- and outer-directed matches. A database can serve the function of recording true identities without being used for suspicionless trawling for hits to unsolved crimes. Such trawling is useful for criminal intelligence, not for authentication of identity. (190)
Intelligence: Investigative Leads and Exonerations
The dominant reason for law enforcement DNA databases is not to keep track of true identities, but to provide investigative leads in unsolved criminal cases. It is, in other words, to make certain biological trace evidence as useful as possible in crime detection. There is much room for argument about the weight this criminal-intelligence interest deserves. No satisfactory studies have measured the actual effectiveness of ordinary trawling and kinship matching. (191) Anecdotal evidence of spectacularly successful trawls abounds. The Green River Killer, (192) the Night Stalker, (193) the Grim Sleeper, (194) and many other serial killers and sexual predators who had eluded detection for decades finally were identified by database trawls. But ramping up a reliable system for collecting crime-scene evidence and large databases has been costly, and the net benefits are hard to estimate. (195)
Despite this uncertainty, courts have been quick to give great weight to claims of the crime-fighting power of the databases and slow to examine the specifics of the databases, such as the length of time during which samples and profiles are retained. A less credulous (or less restrained) judicial stance could prompt more narrowly tailored laws. (196) Nevertheless, if the impacts of advanced database systems on deeply rooted Fourth Amendment interests are somewhat modest, the lack of certainty in the government interests may be tolerable. If there is a plausible case that expanding the scope of the system will be at least moderately effective, judgments as to its advisability, with due regard to the wide range of concerns articulated in the literature, can be left to the legislature.
Along with investigative leads come exclusions of innocent suspects or convicts. Relative Doubt asks whether "partial match searches are necessary for exculpatory purposes to exonerate suspects" and uses the case of Darryl Hunt, who belatedly was exonerated by a near-miss search, to show they are not. (197) The issue for Fourth Amendment reasonableness, however, is not whether all postconviction DNA exonerations necessitate finding the actual criminal. Plainly, they do not. In many situations, there is no reasonable way to explain how the crime-scene DNA could fail to match if the convicted defendant were guilty. In these instances, a database trawl is unnecessary for postconviction exoneration. (198)
But some cases are more ambiguous. Just as the presence of a defendant's DNA at a crime-scene does not always mean the defendant is a criminal, the exclusive presence of someone else's DNA at the crime-scene does not always mean that the defendant is innocent. In a case of a man "convicted of raping a woman who reported that two men had raped her, and that she had not had consensual sex in the relevant period preceding the rape," (199) the police could have picked up the wrong man and still found enough other evidence for a conviction. Being innocent, the man would have been unable to say anything about his alleged coconspirator. Postconviction testing will exonerate the petitioner "if the results reveal two separate DNA profiles, neither of which is the petitioner's." (200) But what if the postconviction testing reveals only one profile? (201) The postconviction DNA testing is consistent with the other evidence of guilt. A database trawl, however, could lead to the man whose DNA is associated with the rape, and his statements might lead to the other rapist and ultimately to an exoneration. (202)
Although we cannot know how often either inner- or outer-directed trawling will exonerate falsely convicted men and women--or prevent future false convictions-the opportunities an advanced database system affords must count at least slightly in the government's favor. In addition, trawls that lead to the correct suspect early in the investigation avoid blind alleys and unnecessary and disturbing investigations of innocent persons. Relative Doubt emphasizes the converse possibility--that the police will waste their resources investigating falsely identified relatives and cause irreparable injury to the lives of these individuals and their families. (203) If investigations are conducted discreetly, however, and if most leads from an advanced database are correct, then the benefits of outer-directed trawling in saving the innocent from becoming suspects may outweigh these costs. (204)
The Reduced Expectation of Privacy
My enumeration of the state's interests pretermitted one of the most prominent considerations in most opinions upholding the acquisition and inner-directed use of DNA databases against Fourth Amendment challenges--the tarnished status of the person imprisoned or on supervised release. According to Relative Doubt, "[t]he rationale justifying such warrantless, suspicionless searches in the case of a direct match--namely, the diminished expectation of privacy and recidivist threat of convicted offenders--is absent when it comes to relatives, who retain the full force of Fourth Amendment protection." (205)
It is true that various opinions cite recidivism statistics in describing the strength of the government's crime-fighting interest. (206) But the governmental interest surely is not limited to determining the identities of offenders who are known to have committed past crimes. Database trawls that net first-time offenders or recidivists who previously have escaped detection advance the same interests as trawls that land criminals with an established history of antisocial acts. (207) There is no static, precisely defined, criminally active segment of the population. People flow into and out of...