Could I sue for libel?

I had someone that has recently posted an outright lie with malicious intent in response to a tagged photo of me on someone Else's facebook page. Essentially, a photo was posted with myself and another person. Because I was tagged in the photo, all comments regarding this photo were sent to my email inbox. Soon after the picture was posted I received emails about comments left on this picture claiming the theft of a large amount of money and wild accusation and name calling. I have never stolen anything from this person, but do have poor relationship with them. I do not have contact with this person to avoid these types of aults, but this person is relentless. I am a credentialed substitute teacher in CA, and think that postings of this sort could be sought after and might possibly disqualify me from gaining employment as much of a substitutes work is gained through word of mouth and reputation. Should I sue for Libel because the post was made on someone else's facebook (social network) page, an outrageous lie that could be proven false, and meant to be malicious?