Could it be shown statistically that cars are used as murder weapons? I heard a story recently in which someone said if they wanted to kill somebody (and get away with it) they would do it with their car.  They cited various statistics about the number of auto-related deaths (including car-on-pedestrians) coupled with additional stats about the number of drivers actually sentenced to any sort of crime...blah, blah, blah. 
My question is this: Is it statistically feasible to demonstrate that cars ARE (statistically speaking) actually used as weapons to commit murder?  
In other words, I realize it may not be possible to demonstrate that any single car-on-pedestrian 'accident' was actually an attempted/committed murder.  Rather, I'm wondering if a method might be imagined in which it could be demonstrated that some percentage of those 'accidents' are actually, in all likelihood, not accidents at all...
 A: This may be a long-shot (practically speaking), but if you could get your hands on the (victim, driver) pairs and had a decent social network search engine, you could calculate the "degrees of separation" between the driver and victim and then construct a null distribution of "degrees of separation" by assuming random assignment of driver and victim from the local population where the accident occurred (e.g., everyone within typical commuting distance). This would correct for the "small town" effect, where everyone has close ties to everyone else.
The key hypothesis is: do the actual driver/victim pairs have fewer degrees of separation than the population at large? If so, it means that either (a) close acquaintances are somehow "synched" in their movements about town [e.g., demographic stratification] (b), at least some of the incidents appear to involve an unusually large number of close acquaintances.
Another approach would be to do logistic regression with "degrees of separation" as the variable, and "probability of accident/victim pariing" on the y axis. A strongly increasing function would suggest a "closeness" effect. 
You would need to corroborate this by seeing if any of the "high relation" pairs actually resulted in a homicide trial and compare it to the overall rate of homicide indictments for pedestrian collisions.   
