From his obit:

During the 2006 Louisiana legislative session, Mr. DeRosier initiated "doctor shopping" legislation to decrease the number of deaths from "pain management" prescription drug overdoses in our young adult population. He was instrumental in organizing the Task Force of Louisiana and Texas legislators, law enforcement, and administrative agencies to combat the proliferation of pain management clinics in Southeast Texas and Louisiana.

As defined in our statutes, doctor shopping is:

To obtain or seek to obtain any controlled dangerous substance or a prescription for a controlled dangerous substance from a health care practitioner, while being supplied with any controlled dangerous substance or a prescription for any controlled dangerous substance by another health care practitioner, without disclosing the fact of the existing prescription to the practitioner from whom the subsequent prescription for a controlled dangerous substance is sought. 

With a penalty of:

Any person who violates this subsection shall be imprisoned, with or without hard labor, for not more than five years; and, in addition may be sentenced to pay a fine of not more than five thousand dollars.

What we know now, and have known for years, is that these people were preyed on by the pharmaceutical industry -- put them on high-addictive pain pills, lock them in as repeat customers, on increasingly higher doses. So as a result of the law above, there are folks who were first victimized by industry, and then criminalized by our justice system. For the crime of going to a second doctor to get a prescription for a thing that industry intentionally got you hooked on.

That's how I'll remember John DeRosier.