Can I get some legal advice regarding slander, among other things?

20 years ago I committed a crime. I did my time for it, came back into society, & never got in trouble again. I remarried, have had a steady job for over 10 years. I regret what I did in the past and wish I could change things, but I can't. Well, now the ex is writing a book about their struggle, and is devoting a large section of the book to me, blaming me for the life of turmoil they have had as late as last year. They had spoken to our local paper and the local news channel. They are lying about what actually happened before I went to prison. Can I sue them for slander, for making the 'facts' much worse than they were? Also, he has posted stories and pictures of me on his facebook page; pictures of me in court, a picture he claims is me in prison, but it was taken years before I got in trouble. Should I seek out a lawyer? I just wanted to run it by you guys first. Thank you! He lost his medical license last year and I guess this book is his idea of a way to make money, no matter who gets hurt.