Here is the final episode where we jump into where they are now, and theories of what happened. 

References:

http://ABCnews.go.com

http://Biography.com

Casey Anthony: An American Mystry

Cellmate Secrets

http://CNN.com

Dr. Oz

Dr. Phil

Presumed Guilty by Jose Baez

http://radaronline.com

http://WFLA.com

http://WPTV.com