Tag Archives: kinship

Rhode Island arrests man following a partial match

A Rhode Island newspaper reports that “[t]he Cranston Police Department has arrested 49-year-old David Finegan, of no permanent address, for the burglary and sexual assault of an 81-year-old woman.” [1] Police “collected [DNA] at the crime scene on May 2.” On June 10, the Rhode Island Department of Health reported that it had a DNA profile from the crime with which to query an offender database. The Rhode Island laboratory did not use software designed for kinship searching, but on July 8, the department advised detectives that it had found a partial DNA match to a female inmate.

The article does not speculate on why it took a month to complete a routine computer search and report the results.Was it because of legal concerns? Was the partial match trawl intentional, or was the discovery inadvertent? Whichever it was, the detectives turned their attention to five male siblings. They discovered that one of them, David Finegan, was “in close proximity . . . on the night of the incident.”

Why this roundabout method of identifying Finegan? He was on parole in July. Was the underlying offense not one that triggered entry into the DNA database? Was there a backlog in entering offender profiles into the database? Whatever the explanation, Finegan had the misfortune of being picked up on July 14 on a parole violation and held for the weekend. Detectives quickly obtained a search warrant and took a sample of DNA from him before he made bail and dropped out of sight. A week later, they learned that it matched the crime-scene DNA.

Pursuing an anonymous tip, police found and arrested Finegan in Providence. He “is being charged with burglary and first-degree sexual assault.” Interestingly, he has an arrest record (including domestic assault, felony DWI, resisting arrest and other assaults) dating back to 1991. A bill that would expand the state database to include arrestees is before House and Senate committees in Rhode Island.


1. Joe Kernan, Arrest Made in Rape of Elderly Woman, Cranston Herald, Dec. 19, 2011


Thanks to Frederick Bieber for informing me of the Cranston Herald article.

DNA Database Overhaul Proposed in Pennsylvania

The majority leader of the Pennsylvania Senate, Dominic Pileggi, just introduced a bill to make major changes in the state’s law enforcement DNA database system. The most significant change is the requirement that individuals who are merely arrested for certain crimes must provide a DNA sample for inclusion in the state database. About half the states now have such laws, although (as noted an earlier posting to this blog) their constitutionality is the subject of continuing litigation. This bill is relatively moderate in its approach to arrestee sampling. There must be a judicial finding of probable cause (or a waiver of the preliminary hearing). The DNA profiles must be removed from the database if there is no conviction. The samples may not be used for kinship searching (a topic of previous postings).

The bill requires the state police to develop and implement procedures for kinship searching. Maryland and the District of Columbia prohibit kinship searching, and California, Colorado, New York, Texas, and Virginia conduct such searches in the absence of explicit statutory authority. Currently there is confusion in Pennsylvania over whether disclosure of near matches to local officials is permissible. The state police contend that “Although familial searching has the potential to be a great investigative tool, implementation at this early stage, without direct legislative approval and a standard national policy, is premature.” Flam (2011). Obviously, the notion that in a federation of states, no state should act before “a standard national policy exists” is somewhat strange. Mimicking the policy adopted by executive action in California, the bill restricts kinship searches to cases in which other investigative methods have failed. Unlike the California policy, however, the bill imposes no artificial floor on the number of autosomal alleles that must match. Instead, it requires administrative rule-making to arrive at more “scientifically valid and reliable” procedures.

A unique provision in the bill states that “No DNA sample or DNA record shall be used for human behavioral genetic research.” This prohibition is superfluous. See Kaye (2006). The bill states that “the tests to be performed on each DNA sample shall be used only for law enforcement identification purposes or to assist in the recovery or identification of human remains from disasters or for other humanitarian identification purposes, including identification of missing persons,” and it defines “Law enforcement identification purposes” as “Assisting in the determination of the identity of an individual whose DNA is contained in a biological sample.” Human behavioral genetic research is not an “identification purpose.”

Whether the state can afford an expansion in the databank is unclear. In the absence of adequate data on the effectiveness of DNA sampling on arrest, a cost-benefit analysis of the proposal is all but impossible. Over ten years ago, the National Commission on the Future of DNA Evidence avoided taking a stand on arrestee sampling on that ground that with large backlogs of crime-scene and offender samples awaiting analysis, adding arrestee samples was premature. The Commission suggested that the issue be readdressed in 2005.


Faye Flam, Colorado D.A. Offers Philadelphia Help in Kensington Strangler Case, Philadelphia Inquirer, Jan. 10, 2011.

David H. Kaye, Behavioral Genetics Research and Criminal DNA Databanks, 69 Law and Contemporary Problems, 259 (2006), reprinted in revised form as Behavioral Genetics Research and Criminal DNA Databases: Laws and Policies, in The Impact of Behavioral Science in Criminal Law 355-387 (N. Faranhy ed., New York: Oxford Univ. Press, 2009).

Senate Bill 775, Pennsylvania General Assembly, introduced Mar. 15, 2011.

How Successful Are Kinship Searches (aka Familial Searches)?

Kinship analysis refers to comparing DNA profiles from different individuals to see if one individual might be a close relative of another. It is done all the time in child-support and missing-remains cases. It is done in criminal cases when a rape victim has a child or aborted fetus.

Using the same principles of genetics, kinship searches can be conducted in a law enforcement database of identifying DNA profiles. For brevity, we can call the convicted offenders (or, in some jurisdictions, arrestees) whose DNA profiles are recorded in a database “database inhabitants.” The profile derived from a crime-scene can be compared with all the database profiles to see (1) if a database inhabitant’s profile is an exact match (the usual “cold hit”) or (2) if there is a close enough match (as shown by kinship analysis) that the crime-scene DNA may have come from a very close relative of a database inhabitant. One group of scientists (Bieber et al. 2006) estimated that kinship matching could generate thousands of useful investigative leads nationally. However, the technique is almost never used, leaving proponents and opponents to rely on their choice of anecdotes about its value and accuracy.

A case in point is a recent law review article that emphasizes “one revealing fact: [Denver’s District Attorney, Mitch Morrissey‘s] familial searches did not work. None of the three matches turned out to point toward a relative, much less the source, of the actual crime-scene sample. . . . [I]t failed in three separate cases . . . .” Erin Murphy (2010).

However, these searches did not use a matching strategy designed and optimized to detect kinship. According to Moreau-Horwin (2011):

In 2009, Morrissey launched a familial search research project with the Denver Police Department. A familial search software program was designed by the DA’s office and the Denver Police Crime Lab. The program would only extend to siblings and parents. When a hit is made, family members could not be questioned unless investigators isolate a suspect using traditional detective work.

This software program resulted in the first case ever to use a deliberate familial search in the United States. In February 2008, several cars were burglarized in a Denver apartment complex. In one car, blood stains were left on the front seat. After extracting the DNA profile, the police ran it through the DNA database, but did not get a match. They then processed the sample as a familial search and a brother of the offender was identified. This led law enforcement to 21 year-old, Luis Jaimes-Tinajero. Police received a court order to take his blood and it was a perfect match to the evidence sample. Jaimes-Tinajero pleaded guilty on September 10, 2009 to criminal trespass and was sentenced to two years probation. Although this case was only designed to test the new familial search software, it would probably have received more publicity had it led to the arrest of a rapist or murderer and not a car burglar who apparently stole only $1.40 in change. 1/

So, is Morrissey’s record 0 for 3 or 1 for 1? It is neither. Surely, there were many cases in which the Denver kinship searches drew blanks or false leads. But the usual, full-match searches do not always produce cold hits either. The latter hit rate depends on the fraction of perpetrators of the crimes who are “database inhabitants.” The former hit rate is much more complicated. It depends on (1) sensitivity–that is, the ability of the kinship matching algorithm to hit on a true relative of the crime-scene profile source in the database; and (2) prevalence–the proportion of relatives of database inhabitants (a) who commit crimes with DNA traces and (b) who are not themselves database inhabitants. The sensitivity of various algorithms can be estimated (Bieber et al. 2006; Curran & Buckleton 2008), but the prevalence is more uncertain. The known fact that the prison population contains a substantial fraction of close relatives is high might mean that there are many more as yet unidentified relatives engaged in criminal activities. (Bieber et al. 2006).

Until a state implements a well designed form of kinship matching in a large number of cases, however, the real-life efficacy of the technique will not be known. The only reference I have seen so far to such information is in a news report of a study in the United Kingdom which “found that, out of 100 searches, more than a dozen led to a suspect.” (Miguel 2007).


1. Ms. Moreau-Howin is a forensic DNA database consultant who maintains a website, DNAforensics.com. For more details on the successful case from a traditional news source, see 9News.com, Car Vandal Nabbed Thanks To Brother’s DNA, Nov. 16, 2009, http://www.9news.com/rss/story.aspx?storyid=127140 (reporting that Luis Jaimes-Tinajero’s “brother was in the system because of a felony conviction for auto theft” and that the “car was one of many at his Denver apartment complex broken into [that] morning”).


9News.com, Car Vandal Nabbed Thanks To Brother’s DNA, Nov. 16, 2009, http://www.9news.com/rss/story.aspx?storyid=127140, last accessed Feb. 20, 2011

Frederick R. Bieber et al., Finding Criminals Through DNA of Their Relatives, 312 Science 1313 (2006).

James M. Curran & John S. Buckleton, Effectiveness of Familial Searches, 48 Sci. & Justice 164 (2008).

Ken Miguel, The controversies surrounding ‘partial DNA,’ ABC7 News, Nov. 13, 2007, http://abclocal.go.com/kgo/story?section=news/drive_to_discover&id=5760664, last accessed Feb. 20, 2011

Raphaele Moreau-Horwin States Using Familial Searches, http://www.dnaforensics.com/StatesAndFamilialSearches.aspx, last accessed Feb. 20, 2011

Erin Murphy, Relative Doubt: Familial Searches of DNA Databases, 109 Mich. L. Rev. 291 (2010).