What you want will determine how you go about this. If you want to change policy, going to your local branch of the ACLU may be the place to start. If you are looking for damages, a good personal injury lawyer would be the place to start.
If you're going for the latter. the Federal Torts Claim Act is the place to start.
http://en.wikipedia.org/wiki/Federal_Tort_Claims_Act
Suing the US federal government is not that hard from a procedural standpoint. The Department of Justice and the U.S. Attorney's office is the counsel of record for the US Government.
Most personal injury lawyers will talk to you for free and there you can get an idea if your case has merit. to find a good personal injury attorney check your state and local bar associations and martendale hubble attorney ratings.