Descriptive statistics for law enforcement officer assaults 1998–2013 and dependent variables
| Variable | Fatal (n=862) | Non-fatal (n=2022) |
|---|---|---|
| Mean age (years)* | 36.9 | 35.6 |
| Mean experience (months)* | 130.6 | 118.3 |
| Male (%) | 94 | 95 |
| White (%) | 85 | 88 |
| Firearm (%)* | 84 | 66 |
| Handgun | 71 | 72 |
| Rifle | 21 | 15 |
| Shotgun | 8 | 13 |
| Dependent variable | Mean | Variance |
| Fatal assaults—all methods | 1.12 | 2.76 |
| Fatal handgun assaults | 0.76 | 1.52 |
| Fatal non-handgun assaults | 0.36 | 0.60 |
| Non-fatal assaults—all methods | 2.52 | 16.73 |
| Non-fatal handgun assaults | 1.20 | 4.48 |
| Non-fatal non-handgun assaults | 1.32 | 5.58 |
*p<0.05. The mean and variance of the dependent variables are presented to illustrate the overdispersion present in the data necessitating the use of negative binomial regression.