The form the police sent me to report my view of the events contained a note that said ``check here to start a criminal investigation''. Since I could never accept the fact that we kill nearly 10,000 people a year in traffic and injure more than half a million (nearly all of them by cars), I figured I'd do something about an obvious threat to public safety and checked the box.
At the end of May, eight months after the accident, I got the summons for July 8, to appear at the trial as a witness against the driver of the car. That was today. After waiting for about an hour (I am glad I brought a ;login: magazine) the trial started. At first, the driver was alone with the judge, the state attorney, and a scribe; later I and the other witnesses (including one of the policemen) were called in and were told that the driver had admitted to the facts stated in the police report and we weren't needed and were free to leave. Of course I stayed until the verdict.
A criminal trial means that it is handled by the state attorney, not by me. I was a witness like the others and didn't need to bring my lawyer or submit any documents. Also, not only did I not have to pay for anything, but I would have been reimbursed for travel and other expenses (I didn't bother).
The driver was found guilty of physical injury resulting from negligence (fahrlässige Körperverletzung). He was sentenced to a penalty of 20 days' salary, and the cost of the trial. (If he had won the state would have paid for the trial.) Also, I expect that the cost of his liability insurance went way up; car liability insurances are pretty good about reclaiming costs with raised premiums. Premiums vary by factors of five or more based on accident history. In addition to all that he probably had to pay civil penalties. According to StVZO §15b, he may also have earned six points in the Flensburg database. When reaching 14 points a driver may lose his license, with 18 he will lose his license.
All in all, this worked out very well. I am still stuck with a knee that is not fully functional (still can't climb as I used to), but it was made extremely clear to my opponent that his behavior was not acceptable. With a bit of luck he won't be able to afford a car now, which means he won't be able to again contribute to those accident statistics.
(Today, two years later, the injury has healed.)