In the U.S., individual states have the option to pass their own familial searching laws. Four states – California, Colorado, New York and Florida have taken the lead in this area. So far, only Maryland has categorically banned familial searching. This ban took place in 2003 and was facilitated with the help of defense attorney Stephen Mercer.
On April 21, 2008, California was the first state to make familial searches legal under certain circumstances. The State of California Department of Justice (DOJ), developed a DNA Partial Match Reporting and Modified CODIS (Combined DNA Index System) Search Policy that may result in investigative information provided to law enforcement officials in unsolved cases. This would only apply to criminal cases where the crime scene DNA profile is a single-source profile and where all other investigative leads have been exhausted. The process developed requires special DNA testing performed on the Y chromosome which produces common male profiles in a paternal lineage and has a biological match with the offender's Y chromosome profile. The policy was developed to address privacy concerns while also providing information that may be useful in solving a violent offense. The DNA "partial match" will result when the profile shares at least 15 STR (Short Tandem Repeat) alleles with a different but potentially related offender profile. The name of the related offender may be released to the investigating agency if the protocol has been followed and all of the conditions are met.
A strong proponent and advocate of familial searches is Mitch Morrissey the District Attorney of Denver, Colorado. Over the years Morrissey has given several excellent presentations on the subject. 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.
As part of the testing phase for the familial search software, the Denver Police Crime Lab also examined 2,000 DNA profiles of unknown offenders found at crimes scenes and ran the samples as a familial search to see if any relatives could be identified. Thirteen familial DNA matches were found. Morrissey has stated that investigations using the familial search software would focus on catching violent criminals such as serial rapists, serial sexual murderers and murderers.
In October 2009, Colorado adopted safeguards when to use familial searches. The chief of the Colorado Bureau of Investigation signed into action the procedures for the DNA Familial Search Policy. The policy outlines that law enforcement agencies must undergo training and must agree to check public records to verify a family relationship before questioning potential suspects.
On December 11, 2009, New York was the third jurisdiction to approve and pass a law that gave law enforcement authority to perform a partial DNA search in their DNA database. This new ruling, approved by New York Commission on Forensic Science, is expected to take effect in spring 2010. The new law will "allow forensic investigators working for the State Police to share information about partial matches with local law enforcement agencies." Ms. Denise E. O'Connell, New York's deputy secretary for public safety and chairwoman of the Commission on Forensic Science stated "that each year, investigators run across 10 to 15 partial matches indicating that the DNA sample could belong to the relative of somebody on file."
Some states have used the technique of familial searches without much publicity and without having passed any official law. In 2005, Florida's DNA Lab technicians were permitted to give investigators the names of convicted offenders who matched a crime scene sample at 21 of 26 alleles. Men who have 21 alleles in common are almost always brothers. Also, in some cases, Florida uses its database to find rape suspects by using the DNA of children born to rape victims to identify their fathers. As of 2007, more than eight rape cases have been solved this way.