IMPROVING HOMICIDE CLEARANCES • WHAT WE KNOW AND COULD KNOW • CHARLES F. WELLFORD • UNIVERSITY OF MARYLAND OUTLINE OF TALK • TRENDS IN HOMICIDES • TRENDS IN HOMICIDE CLEARANCES • VARIATIONS IN 100 LARGEST CITIES • FOUR CITY STUDY OF CLEARANCES • CONCLUSIONS TRENDS IN HOMICIDES Bureau of Justice Statistics Homicide trends in the United States www.ojp.usdoj.gov/bjs/homicide Date of release: September 28 2004 "Homicide victimization, 1950-2002" Year / Homicide Rate / Estimated Number of Homicides 1950 4.6 7020 1951 4.4 6820 1952 4.6 7210 1953 4.5 7210 1954 4.2 6850 1955 4.1 6850 1956 4.1 6970 1957 4 8060 1958 4.8 8220 1959 4.9 8580 1960 5.1 9110 1961 4.8 8740 1962 4.6 8530 1963 4.6 8640 1964 4.9 9360 1965 5.1 9960 1966 5.6 11040 1967 6.2 12240 1968 6.9 13800 1969 7.3 14760 1970 7.9 16000 1971 8.6 17780 1972 9 18670 1973 9.4 19640 1974 9.8 20710 1975 9.6 20510 1976 8.8 18780 1977 8.8 19120 1978 9 19560 1979 9.7 21460 Bureau of Justice Statistics Homicide trends in the United States www.ojp.usdoj.gov/bjs/homicide Date of release: September 28 2004 (continue) Year / Homicide Rate / Estimated Number of Homicides 1980 10.2 23040 1981 9.8 22520 1982 9.1 21010 1983 8.3 19308 1984 7.9 18692 1985 8 18976 1986 8.6 20613 1987 8.3 20096 1988 8.5 20675 1989 8.7 21500 1990 9.4 23438 1991 9.8 24703 1992 9.3 23760 1993 9.5 24526 1994 9 23326 1995 8.2 21606 1996 7.4 19645 1997 6.8 18208 1998 6.3 16974 1999 5.7 15522 2000 5.5 15586 2001 5.6 16037 2002 5.6 16204 "* Rate per 100,000 population" "Source: FBI, Uniform Crime Reports, 1950-2002" Homicide victimization 1950-2002 Graph showing homicides vitctims from 1950 through 2002 Homicide Rate TRENDS IN CLEARANCES Bureau of Justice Statistics Homicide trends in the United States www.ojp.usdoj.gov/bjs/homicide Date of release: September 28 2004 Percent of Homicides Cleared by Arrest Year Percent cleared 1976 79 1977 76 1978 76 1979 73 1980 72 1981 72 1982 74 1983 76 1984 74 1985 72 1986 70 1987 70 1988 70 (cont.) 1989 68 1990 67 1991 67 1992 65 1993 66 1994 64 1995 65 1996 67 1997 66 1998 69 1999 69 2000 63 2001 62 2002 64 "Source: FBI, Supplementary Homicide Reports, 1976-2002" See the methodology section in 'Additional Information About the Data' for weighting and imputation procedures used. by Arrest graph showing percent of homicides cleared by arrest from 1976 to 2000 Bureau of Justice Statistics Homicide trends in the United States www.ojp.usdoj.gov/bjs/homicide Date of release: September 28 2004 Homicide Victims by Circumstance Year- Felony Argument- Gang- Other Unknown 1976- 3327 9106 129- 4630- 1588 1977- 3189 8929 180- 4112- 2709 1978- 3262 8950 194- 4447- 2706 1979- 3623 9237 264- 4534- 3803 1980- 4070 10299 221- 4963- 3486 1981- 3882 9519 280- 4835- 4005 1982- 3721 8613 238- 4322- 4116 1983- 3479 8469 260- 3058- 4044 1984- 3382 8211 223- 2708- 4166 1985- 3388 8284 288- 2690- 4329 1986- 3992 8602 357- 3015- 4644 1987- 3935 8087 395- 2678- 5005 Homicide Victims by Circumstance (Cont.) 1988- 3932 7872 428- 3010- 5437 1989- 4593 8433 678- 2709- 5086 1990- 4867 8988 905- 2867- 5812 1991- 5283 8806 1192- 3027- 6393 1992- 5143 7950 994- 3110- 6563 1993- 4721 8309 1362- 3403- 6735 1994- 4303 7529 1340- 3622- 6536 1995- 3829 6753 1331- 3451- 6246 1996- 3690 6620 1091- 2331- 5918 1997- 3413 6103 999- 1888- 5807 1998- 2998 5845 834- 2048- 5245 1999- 2642 4993 837- 2455- 4594 2000- 2626 4988 846- 2331- 4795 2001- 2694 4840 1071- 2246- 5187 2002- 2656 4752 1119- 2371- 5305 "Source: FBI, Supplementary Homicide Reports, 1976-2002" See the methodology section in 'Additional Information About the Data for weighting an imputation procedures used. Homicide Victims by Circumstance graph showing homicide victims by circumstance (felony, argument, gang, other, unknown) from 1976 to 2002 VARIATIONS IN 100 LARGESTVARIATIONS IN 100 LARGESTCITIESCITIES Graph showing rape clearance rate from 1970 to 2002 Graph showing robbery clearance rate from 1970 to 2002 Graph showing assault clearance rate from 1970 to 2002 Graph showing burglary clearance rate from 1970 to 2002 Graph showing larceny clearance rate from 1970 to 2002 Graph showing car theft clearance rate from 1970 to 2002 Graph showing homicide clearance rate from 1970 to 2002 FACTORS ASSOCIATED WITH HOMICIDE CLEARANCE • JIM CRONIN, PERF • JRSA • ROLE OF STATE STATISTICAL ANALYSIS CENTERS DESIGN • DEVELOPMENT OF TWO INSTRUMENTS (OVER 250VARIABLES PER CASE) • USE OF FOCUS GROUPS –INCIDENT –INVESTIGATION • ORGANIZATIONAL DIMENSION • NOW SIX YEARS OLD Homicide and Total Clearance Rate Levels, 1994, for 20 of the Largest Cities in the United States Homicide Clearance Level Total Clearance Level - High / Medium / Low High - City A Austin Dallas / Jacksonville Philadelphia San Jose / City C Boston Medium - El Paso / Memphis Phoenix Seattle / San Diego Washington, D.C. Low - City D / Columbus Houston / City B San Antonio San Francisco *Cities A, B, C, and D are the cities selected for study. Significant Variables and Their Effect Variable -Victim a gang or drug organization member ** Percent Change 582 Variable - White v. Hispanic * Percent Change - 166 Primary cause of death Variable - Rifle v. handgun ** Percent Change - 231 Variable - Knife v. handgun ** Percent Change - 114 Variable - Personal weapon v. handgun ** Percent Change - 452 Variable - Weapon identified or suggested in police report ** Percent CHange - 217 Variable - Decedent in possession of a weapon ** Percent Change - 92 Variable - Drugs not a circumstance * Percent Change - 117 Significant Variables and Their Effect on Homicide Clearance (cont.) Variable Percent Change Location (private v. public)** 171 Number of eyewitnesses (at least 1 vs. 0)** 85 Preemption for anticipated retaliation ** 354 Conflict over money or property other than drugs ** 155 Offender defending themselves ** 288 Victim was a bystander killed inadvertently * 103 Attempt to get money to buy drugs * 256 Number of detectives assigned to case Significant Variables and Their Effect on Homicide Clearance (Cont.) Variable Percent Change 3 v. 1 ** 121 4 v. 1 * 210 11 v. 1 * 105Time for detective to arrive on scene 30 to 60 minutes v. <30 minutes ** -62 Detective described crime scene in notes * 190 Detective followed up on witness information ** 117 Significant Variables and Their Effect on Homicide Clearance (Cont.) Variable Percent Change Warrant requested for a suspect ** 4230 Crime scene Bar/club v. public area (street or park)* 325 Residence v. public area ** 300 First officer notified the homicide unit ** 127 First officer notified medical examiner’s office ** 134 Significant Variables and Their Effect on Homicide Clearance (Cont.) Variable Percent Change First officer notified crime lab ** 146 First officer attempted to locate witnesses ** 147 Measured crime scene ** 63 Weapon found at crime scene ** 189 Witness at scene provided valuable information ** 375 Circumstances of death ** 196 Motivation for death ** 189 Identification of offender ** 2711 Identification of victim ** 63 Significant Variables and Their Effect on Homicide Clearance (Cont.) PercentVariable Change Location of offender ** 292 Neighborhood survey provided valuable information ** 60 Witness found who was not at crime scene (at least 1 v.0)* 32 Neighbors of victim interviewed ** 66 Family members, friends, coworkers, roommates, or neighbors provide valuable information ** 163 Computer check conducted on suspect ** 571 Computer check conducted on guns ** 124 Computer check provided valuable information ** 245 Computer system used Significant Variables and Their Effect on Homicide Clearance (Cont.) Variable Percent Change Local Criminal Justice Information System (CJIS) ** 46 Attending physician/medical personnel interviewed ** 101 Detective present at postmortem examination ** 90 Specimens collected from decedent ** 45 Projectiles recovered from decedent ** 67 Medical examiner prepared a body chart ** 114 Confidential informants provided valuable information ** 264 Surveillance used ** 181 Reduced Model Predicting Clearance • Offender African American • Body chart of victim prepared • Computer check on decedent • Computer check on suspect ** • Computer check on witnesses ** • Computer check on guns • Used local Criminal Justice Information System (CJIS) * • Witness provided valuable information ** • Friends/acquaintances interviewed • Neighbors interviewed • Three or more detectives assigned to the case • Homicide occurred in a private residence * • Eyewitness to the homicide • Homicide was not drug related * • Chance of solving the case CONCLUSIONS • POLICE MATTER • SOME DO BETTER THAN OTHERS • CIRCUMSTANCES ARE IMPORTANT BUT NOT OVERWHELMINGLY SO • PROCESS VS. SUBSTANCE • ORGANIZATIONAL FACTORS NEED ATTENTION