IAPE Evidence Blog

United States Depart­ment of Justice

More than 2,000 state and local law enforce­ment agen­cies responded to a sur­vey [1] to:

1. Esti­mate the num­ber of unsolved homi­cide, rape and prop­erty cases [2] nation­wide that con­tain foren­sic evi­dence that has not been sub­mit­ted to a crime lab­o­ra­tory for analysis.

2. Deter­mine the exis­tence of poli­cies and pro­ce­dures regard­ing the pro­cess­ing, sub­mis­sion to a lab and reten­tion of foren­sic evidence.

The sur­vey showed that agen­cies had not sub­mit­ted foren­sic evi­dence (includ­ing DNA, fin­ger­prints, firearms and tool­marks) to a crime lab in:

* Four­teen per­cent of open, unsolved homi­cides.
* Eigh­teen per­cent of open, unsolved rapes.
* Twenty-three per­cent of open, unsolved prop­erty crimes.

There are rea­sons why a law enforce­ment agency may not sub­mit foren­sic evi­dence to a lab. The evi­dence may be con­sid­ered not pro­ba­tive, charges may have been dropped or a guilty plea entered. How­ever, the researchers who con­ducted the NIJ-funded sur­vey also con­cluded that some law enforce­ment agen­cies may not fully under­stand the value of evi­dence in devel­op­ing new inves­tiga­tive leads.

Learn more about why evi­dence may not have been submitted.

The sur­vey also revealed that:

* Only four out of 10 law enforce­ment agen­cies have a com­put­er­ized sys­tem for track­ing foren­sic evi­dence either in their inven­tory or after it is sent to the crime lab. Learn more about the use of com­put­er­ized systems. 

* Poli­cies and prac­tices for evi­dence reten­tion var­ied widely from juris­dic­tion to juris­dic­tion. Learn more about poli­cies and practice.

* There are steps that law enforce­ment agen­cies, foren­sic lab­o­ra­to­ries and pros­e­cu­tors can take to improve the use of foren­sic evi­dence. Read a sum­mary of the study recommendations.

The sur­vey did not determine:

* How many of the open cases would be solved or yield inves­tiga­tive leads if evi­dence in them were to be sent to the lab.

* The num­ber of cases in which evi­dence was ana­lyzed in the past, but which now, with more advanced tech­nol­ogy, might be solved or yield inves­tiga­tive leads. Read more about the poten­tial value of the evidence.

Why Evi­dence May Not Be Sent to a Lab
There are many rea­sons why evi­dence col­lected from a crime may not be sub­mit­ted to a lab­o­ra­tory for analy­sis. Sub­se­quent inves­ti­ga­tion may have shown that the evi­dence would not be pro­ba­tive, charges against an alleged per­pe­tra­tor may have been dropped, the sus­pect may have pled guilty, or, in a rape case, the issue may be “con­sent” and, there­fore, analy­sis of the evi­dence may have been con­sid­ered not probative.

How­ever, the study showed that some law enforce­ment agen­cies do not fully under­stand the poten­tial value of foren­sic evi­dence in devel­op­ing new leads in a crim­i­nal inves­ti­ga­tion; for example:

* Forty-four per­cent said one of the rea­sons they did not send evi­dence to the lab was because a sus­pect had not been identified,

* Fif­teen per­cent said they did not sub­mit evi­dence because analy­sis had not been requested by a prosecutor.

We know that DNA evi­dence can iden­tify a sus­pect in a “no sus­pect” case or link a per­pe­tra­tor to a spe­cific crime through CODIS, the national DNA data­base, and latent prints can iden­tify unknown per­pe­tra­tors through auto­mated sys­tems like the national Inte­grated Auto­mated Fin­ger­print Iden­ti­fi­ca­tion Sys­tem (IAFIS). The knowl­edge gap revealed in some of these find­ings — par­tic­u­larly, as the sur­vey reveals, among the nation’s small (less than 25 offi­cers) agen­cies — could be due to a lack of train­ing. Spe­cial­ized train­ing in these cases may have been ben­e­fi­cial and led to a dif­fer­ent out­come. In another find­ing from the study, 11 per­cent of the agen­cies reported that one of the rea­sons they do not sub­mit evi­dence for analy­sis is because of the lab’s inabil­ity to pro­duce timely results, and 6 per­cent said the lab was not accept­ing new evi­dence due to back­log issues. (See About the Back­log on DNA.gov).

See Rea­sons Why Law Enforce­ment Agen­cies did not Sub­mit Foren­sic Evi­dence for Unsolved Cases (pdf, 81 pages) in the full report.

Many Agen­cies Lack Com­put­er­ized Sys­tems
Com­put­er­ized infor­ma­tion sys­tems enhance the abil­ity of police agen­cies to man­age, track and mon­i­tor foren­sic evi­dence in crim­i­nal cases. The sur­vey revealed that more than half of law enforce­ment agen­cies (56 per­cent) did not have a com­put­er­ized infor­ma­tion sys­tem that was capa­ble of track­ing foren­sic evi­dence inven­tory. Large agen­cies (100 or more sworn offi­cers) were much more likely to have a com­put­er­ized sys­tem, with nearly three out of four report­ing that their infor­ma­tion sys­tem allowed track­ing of foren­sic evidence.

For the agen­cies that do have a com­put­er­ized infor­ma­tion sys­tem, the sur­vey did not reveal the exact capa­bil­i­ties, such as whether they were able to spec­ify what evi­dence has been tested (or not tested) in a case, how long evi­dence in a case has been in stor­age, and the sta­tus of cases. The sur­vey also did not deter­mine, for the 44 per­cent of agen­cies that do have a com­put­er­ized sys­tem, whether these sys­tems are inte­grated with more cen­tral­ized police records man­age­ment systems.

See Law Enforce­ment Infor­ma­tion Sys­tems and Foren­sic Evi­dence (pdf, 81 pages) in the full report.

Many Agen­cies Lack Pol­icy, Prac­tice
Poli­cies and prac­tices for retain­ing evi­dence var­ied widely from juris­dic­tion to juris­dic­tion. In addi­tion to the need to retain evi­dence in unsolved crimes, there are an increas­ing num­ber of states that have passed laws requir­ing the indef­i­nite stor­age of foren­sic evi­dence used in crim­i­nal con­vic­tions. About a third of the agen­cies (38 per­cent) said they had an evidence-retention pol­icy regard­ing the preser­va­tion of bio­log­i­cal evi­dence in cases where the defen­dant was found guilty, and 16 per­cent said they were unsure if they had such a policy.

Among agen­cies that do have a pol­icy regard­ing the reten­tion of evi­dence post-conviction, 51 per­cent reported that the pol­icy was gov­erned by state statute, 43 per­cent said evi­dence was retained due to agency pol­icy, and 5 per­cent said the pol­icy was in place as a result of a legal decision.

See Law Enforce­ment Poli­cies for Retain­ing Bio­log­i­cal Evi­dence (pdf, 81 pages) in the full report.

Rec­om­men­da­tions for the Future

The researchers made a num­ber of recommendations:

* Increased train­ing for law enforce­ment on the ben­e­fits and use of foren­sic evi­dence, includ­ing guide­lines for pri­or­i­tiz­ing cases for analysis.

* Cre­ation (or improve­ment) of infor­ma­tion man­age­ment sys­tems to track and mon­i­tor foren­sic evidence.

* Devel­op­ment of bet­ter pro­to­cols to ensure timely sub­mis­sion of pro­ba­tive foren­sic evi­dence to the lab and stan­dard­ized poli­cies for evi­dence retention.

* More stor­age capac­ity for ana­lyzed and unan­a­lyzed foren­sic evidence.

* Bet­ter coor­di­na­tion within a law enforce­ment agency and among the police, foren­sic lab and the prosecutor’s office. Coor­di­na­tion could involve ded­i­cated staff for case man­age­ment, reg­u­lar team meet­ings for case review and case track­ing sys­tems to allow information-sharing across these agencies.

* More research to bet­ter under­stand (1) what pro­por­tion of the open cases might be solved or yield inves­tiga­tive leads if evi­dence was sub­mit­ted to a lab and (2) how such cases should be pri­or­i­tized for testing.

See Study Impli­ca­tions (pdf, 81 pages) in the full report.

The Poten­tial Value of Unan­a­lyzed Evi­dence not Addressed
The sur­vey does not reveal how many open cases with unan­a­lyzed evi­dence would be solved or yield inves­tiga­tive leads if evi­dence were to be sent to the lab. It also does not address the num­ber cases in which evi­dence was ana­lyzed in the past, but which now — with the ben­e­fit of larger offender data­bases and new foren­sic tech­nolo­gies — might be solved or yield inves­tiga­tive leads; for exam­ple, a latent print run through IAFIS sev­eral years ago with no suc­cess­ful match could yield a hit now. More research would help us bet­ter under­stand these issues.

See Study Lim­i­ta­tions (pdf, 81 pages) in the full report.

About the Sur­vey Responses
The 72 per­cent response rate for the sur­vey is con­sid­ered very good; 2,250 of the 3,094 state and local law enforce­ment agen­cies that the sur­vey was sent to responded. In some juris­dic­tions, how­ever, the num­ber of unsolved cases con­tain­ing unan­a­lyzed evi­dence was based on esti­mates; and some of the larger county and state agen­cies reported dif­fi­culty pro­vid­ing infor­ma­tion about rape and prop­erty cases because they do not main­tain these cases in a cen­tral­ized system.

See Study Lim­i­ta­tions (pdf, 81 pages) in the full report.

Notes

[1] Strom, Kevin J., Jeri Ropero-Miller, Shel­ton Jones, Nathan Sikes, Mark Pope and Nicole Horstmann, The 2007 Sur­vey of Law Enforce­ment Foren­sic Evi­dence Pro­cess­ing (pdf, 81 pages), Final Report, Wash­ing­ton, DC: U.S. Depart­ment of Jus­tice, National Insti­tute of Jus­tice, Sep­tem­ber 2009, 228415.

[2] Unsolved cases were defined as cases that had not been offi­cially cleared by the law enforce­ment agency.

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