Role and Impact of Forensic Evidence in the …

1 Role and Impact of Forensic Evidence in the Criminal Justice ProcessJustice Research and Statistics AssociationOctober 23, 2009 Joseph Peterson, Ira Sommers, Donald Johnson, Deborah BaskinSchool of Criminal Justice and CriminalisticsCalifornia State University, L ALos Angeles, CABackground Forensic sciences have seen dramatic scientific breakthroughs in last 25 years The CSI phenomenon has sensitized CJ personnel and public to Forensic science Still, lab resources have not kept pace with submissions and backlogs >500K Many federal efforts (DNA Initiative, Coverdell Act, etc.) have assistedBackground (continued) Many professional programs have evolved to elevate quality of Forensic lab results Still, scandals have shaken crime lab profession (FBI, West Virginia, Houston PD, etc), causing concern over reliability of Evidence Supreme Court decisions (Daubert, etc.)

2 Have named judges as gatekeepers to assess quality and reliability of scientific Evidence National Academy of Sciences panel issued landmark critical report in February 2009 National Institute of Justice Research Solicitation It has been 25 years since there was an assessment of the uses and effects of scientific Evidence on police and courts An estimated $ billion is spent annually on Forensic services but question remains: What are its uses and Impact ? NIJ solicited proposals in 2006 to assess the role and Impact of Forensic servicesNIJ Project GoalsDetermine: Percent of crime scenes with Forensic Evidence Varieties of Forensic Evidence recovered from different categories of major crimes Track Evidence collection, analysis and attrition of Evidence from incident thru lab into courts Identify types of Forensic Evidence that contribute most often to successful case outcomes (relative to its availability)Prevalence of Crime Labs and Scientific Evidence Presently are about 400 crime laboratories nationwide examining M requests annually Studies in 1980s found Evidence collected in only about 20-30% of cases, varying greatly by offense type Huge investment in DNA over past five years Controlled substances (70%)

3 Still dominate lab caseloads, followed by biological Evidence , firearms and fingerprintsPresent NIJ Study Thirty (30) month project Oct 06-Apr 09 Three study sites selected representing city, county, and state-wide laboratory systems: Los Angeles County, CA Indianapolis, IN Indiana State Police Lab and local jurisdictions of South Bend, Ft. Wayne, and EvansvilleData Collection Prospective analysis of (2003) official records, data tracking police incidents (into/out of laboratory) to final case disposition Stratified, random sample (homicides, agg. assaults, rapes, robberies, & burglaries) of more than 4,000 incidents selected from police files in each of five study sites Police incident, crime scene, investigator, laboratory, prosecutor, and court files reviewedCritical Decision Points Crime scene Evidence collection Laboratory acceptance, prioritization and analysis (criminalist, detective, prosecutor)

4 Police decision to investigate, arrest and/or exclude suspects Prosecutor decision to file charges, accept pleas, or take cases to trial Fact-finders/pros and defense attorneys use of scientific Evidence , reports and testimonyIndependent Variables Key Individual Case-Level Demographics of suspect/victim, offense type, report/response time, witnesses, information/ Evidence collected, scientific results, offender and case processing characteristics, key decisions, demographicsKey Dependent VariablesLogistic Regression Analysis If reported crime led to arrest If arrest referred to prosecutor If prosecutor filed charges Manner of disposition (plea/trial) Convict/no convict If convicted, nature of sentence Length of sentenceIncidents Randomly Sampled by Jurisdiction (2003*)LAINEVFWSBHOM24571143832 RAPE231150757076 ROBB528335807365 ASSLT23032310895103 BURG489350142144138 Per Cent Offenses with Crime Evidence CollectedLA(%)IN(%)EV(%)FW(%)SB(%)HOM969 7100100100 RAPE5173756672 ROBB1928442535 ASSLT2533263832 BURG2123151516 Phys Evid/Substrates Collected Indianapolis Crime ScenesHOM (%)RAPE (%)ROBB (%)ASSLT (%)BURG (%) Filtering of Forensic Evidence in Los Angeles HOM (%)RAPE (%)ASSLT (%)ROBB(%)BURG (%)CLLCT SCENE9651251921 SBMIT LAB924913819 EXAM80227710 Major Filtering of Evidence in EvansvilleHOM (%)RAPE (%)ASSLT (%)ROBB (%)BURG (%)

5 CLLCT SCENE10075264415 SBMIT LAB100118133 EXAM100118133 Crime Lab Results (Indianapolis)EXAM (#)INDIV (#)+ID (#)-ID (#)HITS (#)HOM55/5631480 RAPE25/4461100 ROBB43/44323600 ASSLT33/39141001 AFISBURG47/47353604 AFISBiVariate Relationships Cases With/Without Forensic Evidence Collected, Submitted, and Examined Arrest Referral Charge Outcome SentenceArrests Rates for Offenses With and Without Crime Scene EvidenceLA(%)IN(%)EV(%)FW(%)SB(%)HOM*46/ 4073/100100/047/078/0 RAPE56/5078/4425/1122/829/5 ROBB50/1945/963/1644/735/5 ASSLT51/7173/3775/3658/2039/24 BURG13/912/529/624/69/6 Bivariate Relationships: Crime Scene Evidence (Y/N) and Case Progress (Number of Sites Where Significant*)HOMASSLTRAPEROBBBURGARRST** REFRL**NS*NSCHRGENS*NS**NSCases with Crime Scene Evidence as Significant Predictor of Arrest Los Angeles - Homicide*, Robbery Indianapolis - Rape, Assault, Robb, Burg Evansville - Assault, Robbery, Burglary Fort Wayne - Assault and Robbery South Bend - Rape and Robbery*Firearms, Materials EvidenceCases Where Crime Scene Evidence Significant Predictor of Arrest -Fraction Examined Prior to ArrestsASSLTRAPEROBBBURGLA2/131 INDY7/15813/1039/622/23 EVANS1/506/291/13FW0/334/12SB1/170/10 Explaining Higher Arrest Rates For Cases with For.

6 Evidence , But Not Yet Examined Are these cases different in fundamental ways? How/who reports them How suspects are identified/apprehended Relationship between victim and suspect Does physical Evidence have immediate value even though not yet examined? Is quantum of proof for an arrest satisfied with presumptive scientific Evidence ?Role of Forensic Evidence in Direct vs. Descriptive Arrests Hypothesis: Forensic Evidence of greater value in direct observation cases Direct: Suspect apprehended, admission, suspect surrender, arrest in another case, police observe, traffic stop, recovered property Descriptive: Vehicular description, citizen observation, photo ID, suspect description, line-upCombining Smaller Jurisdictions All Part of Indiana State Lab System South Bend Fort Wayne EvansvilleCOMBINED INDIANA SITES.

7 FOR EVID PREDICTORS OF ARREST (Sig Level**)HOMASSLTRAPEROBBBURGC rime Scene Evidence **LaboratoryEvidence**Lab Examine Evidence **Biolog Crime Scene**Prints Crime Scene**Biolog Lab Evidence **Unique Indi-viduality**Individualized/Associati ve Lab Results, Arrest and ConvictionTotalArrestConvictRateAssault5 /8593267%Burglary18/12638450%Hmicide80/4 00574681%Rape16/60211982%Robbery14/10811 1982%Individualized/Associative Evidence and Conviction Rate Single Form - 67% (convictions/arrests) 20% firearms 20% biology 57% latent prints Two or More Forms - 86% 29% biology 29% firearms 14% latents 29% combination of aboveTotal Individualized Evidence By Offense Assault - Bio/Firearms - 5 cases Burglary - Latent Prints - 18 cases Homicide - Latents, Firearms, and Bio 80 cases Rape - Bio/Latents - 16 cases Robbery - Latents - 14 casesPlea/Trial and Sentencing Generally, Forensic Evidence strengthens a case and influences cases to go to trial (Assault, Rape) Generally, examined Forensic Evidence leads to more severe sanctions -Assault, Burglary (two jurisdictions)Citizen Polls and Surveys Field poll (CA) queries of 1201 randomly selected California registered voters (telephone)

8 As to their views of reliability and importance of Forensic Evidence and: Television viewing habits Jury service experience C J employment Crime victimizationCitizen Poll Regression Results Citizens generally perceive Forensic Evidence as much more reliable than other forms of testimonial Evidence Citizens who watch more hours of TV programming regard Forensic Evidence as more reliable Citizens who watch justice themed TV crime shows were more than twice as likely to convict than those who didn t Implications for Policy/Practice Collection of Physical Evidence Lab Examination of Evidence Investigations of Crimes Prosecution and Adjudication CSI EffectInvestigation for and Collection of Physical Evidence Most scenes have physical Evidence and much is collected to

9 Insure it does not perish and to comply with modern Forensic science expectations Much physical Evidence is filtered between crime scene and laboratory analysis - most by crime scene technicians and detectives Firearms, latent (finger) prints and biological Evidence is most often collected and submitted Prosecutors play major role in influencing decisions to collect, submit and analyze evidenceCriminal Investigations Physical Evidence adds value and momentum to investigation even before/without lab analysis Controlling for other investigative factors, Forensic Evidence associated with arrest in many cases Other case characteristics (victim and witness reports) are also important predictors of arrest Forensic Evidence is valuable at arrest, but less so at subsequent stages of prosecution/adjudication Forensic Evidence (latent prints and firearms)

10 From robberies consistently associated with arrest in all study sitesLaboratory Analysis Most examinations of Evidence will await determination that results of analysis are needed A comparatively small percentage of examinations result in individuality of Evidence and linkage to suspect/victim Inquiry into data bases seldom provide identity of unknown offenderProsecutions and Adjudications Prosecutors are very mindful of CSI Effect and expectations of court/jurors Charging decisions are heavily influenced by overall convictability of case Value of Forensic Evidence as predictor diminishes after charging Stronger Evidence cases, including Forensic Evidence , more often result in trial Sentence/plea bargaining may be influenced by presence of lab analysis and reportInfluence of CSI Effect Investigators and crime scene technicians very aware that arrests and prosecutions may not be sustained unless Evidence collected/proper procedures followed Prosecutors believe Forensic Evidence is central to plea and trial conviction Prosecutors are pressed to state proper procedures followed in cases, even those lacking Forensic Evidence Prosecutor view of case needs influences actions of crime scene, investigators and laboratory Thank you!