1) Co-defendant 2) Defendant 3) Suspect 
n. when more than one person or entity is sued in one lawsuit, each party sued is called a codefendant.
• (n.) A joint defendant.
When more then one person are involved in a common legal proceeding, they are called codefendants.
Co`de·fend'ant noun A joint defendant. Blackstone. 
One of two or more defendants charged with the same crime or sued in the same claim. Also called joint defendant.
[n] - a defendant who has been joined together with one or more other defendants in a single action
co-defendant noun a defendant who has been joined together with one or more other defendants in a single action
a joint defendant.