MINNEAPOLIS (AP)  A nurse who authorities say visited suicide chat rooms on the Internet and encouraged depressed people to kill themselves is under investigation in at least two deaths and may face criminal charges that could test the limits of the First Amendment.

Investigators said the nurse, William Melchert-Dinkel, 47, feigned compassion for those he chatted with, while offering step-by-step instructions on how to take their lives.

Legal experts said prosecuting such a case would be difficult because Mr. Melchert-Dinkel did not physically help kill anyone. In the meantime, his nursing license has been revoked.

“Nothing is going to come of it,” Mr. Melchert-Dinkel told The Associated Press. “I’ve moved on with my life, and that’s it.”