Table 1.
Sample Descriptive Statistics: Means (Standard Deviation)a
| Variable | Assault | Homicide | ||
|---|---|---|---|---|
| Mean | (SD) | Mean | (SD) | |
| Level 1: Offender Characteristics | ||||
| Arrest | .36 | – | .68 | – |
| Black | .35 | – | .39 | – |
| White | .63 | – | .59 | – |
| Other Race | .02 | – | .03 | – |
| Age | 30.40 | (11.77) | 29.33 | (10.32) |
| Male | .53 | – | .58 | – |
| N | 876,524 | 2,134 | ||
| Level 2: Incident Characteristics | ||||
| Co-offender Characteristics | ||||
| Mean Age | 30.38 | (10.56) | 29.32 | (8.91) |
| Proportion Male | .53 | (.17) | .58 | (.19) |
| Proportion White | .63 | (.43) | .59 | (.43) |
| Proportion Black | .35 | (.43) | .39 | (.42) |
| Proportion Other Race | .02 | (.11) | .03 | (.14) |
| Offense Characteristics | ||||
| Weapon | .15 | – | .76 | – |
| Alcohol | .14 | – | .07 | – |
| Drug use | .02 | – | .09 | – |
| Gang | .00 | – | .01 | – |
| Aggravated assaultb | .14 | – | – | – |
| Simple Assault | .76 | – | – | – |
| Intimidation | .13 | – | – | – |
| Victim Characteristics | ||||
| Number | 1.77 | (.61) | 1.37 | (.74) |
| Mean Age | 30.10 | (11.99) | 32.09 | (20.56) |
| Proportion White Female | .33 | (.34) | .18 | (.35) |
| Proportion Hispanic | .09 | (.37) | .07 | (.24) |
| Proportion Resident | .78 | (.38) | .71 | (.43) |
| Injury | .51 | – | – | – |
| Stranger | .05 | – | .11 | – |
| N | 438,262 | 1,067 | ||
Note: SD=Standard deviation (omitted for dummy variables)
a
Means for dummy measures can be interpreted as the proportion of the sample coded 1 on that variable.
b
Because the NIBRS data do not use a hierarchy rule when recording offense type, offense categories are not mutually exclusive and may sum to a proportion greater than 1.