Well, I think certain roles are chosen for us. The moment I read Pete Campbell I thought: I can do this, this is mine. And in Money, too. The truth is I turn down a lot of projects. If a character doesn't have some kind of internal struggle, it's no good for me.

The youngest of six children he has four sisters Andrea Colette Elise and Theresa and a brother Nathan. Personal life
Kartheiser dated his The Hairy Bird co-star Rachael Leigh Cook for four months in 1998. Kartheiser later landed a regular role on the supernatural drama series Angel in 2002.