Who is the ex-boyfriend of Casey Anthony...?

Not Jesse Grund, not Tony (either of the Tony's), not JP, not Ricardo, but there was someone she was sick and crying over during a text session with Amy back in March. Then later, someone mentioned she got very agitated when she bumped into this person at a party in maybe May or June?

I know I read about him when I was reading through all the case files, but I cannot remember which transcript had the info - it was not the Army guy either, the one she emailed back and forth with calling him the sweetest guy in the world - this was someone who really burned Casey bad, and I was going to look and see if he could possibly be Caylee's dad. Because the searches for neck breaking and all the rest I believe happened in March right around the time Casey was texting Amy about how much she hurt over this guy.

I am just wondering if this could play a part in motivation - if she really hated, despised the father of her child and wanted to destroy him in some way...

Just found the transcript that does not mention him by name but I was mistaken on the dates - this was end of April/beginning of May where Casey says she has her closure. And there is a mention of "Justin" - it was someone that Casey referred to in chat converations and IM as well as having broken her heart.