They cited two comments she posted on Facebook, the popular social networking site, she said.

In the first, posted Jan. 21, Gadsden wrote, “Does anyone know where I can find a very discrete hitman? Yes, it’s been that kind of day…”

Five comments followed the message, suggesting those to whom she was linked understood the joke. One said she was “ROFL,” shorthand for “rolling on the floor laughing.”

In the other comment, posted one month later, Gadsden wrote, “had a good day today, DIDN’T want to kill even one student :-). Now Friday was a different story.”