Key developments in medical marijuana litigation before the U.S. Supreme Court:

. May 14, 2001: Supreme Court said it was illegal to distribute medical marijuana to sick and dying patients.

. Oct. 14, 2003: Supreme Court let stand a lower court decision saying doctors have a First Amendment right to discuss or recommend marijuana to their patients without the threat or fear of federal sanctions.

. June 6, 2005: Supreme Court ruled that medical marijuana users in states allowing it are not immune from federal prosecution because Congress has deemed it illegal.

States that permit the medical use of marijuana are: Alaska, California, Colorado, Hawaii, Maine, Montana, Nevada, Oregon, Rhode Island, Vermont and Washington.