Not if the case were already underway. You would have file a new or amended lawsuit in order to name the 'witness' as a defendant or co-defendant. it is doubtful that an amended lawsuit would be...
In a word, money. Legally, they seek "compensation" for their losses.
Not all plaintiffs seek money damages (called "legal relief") from defendants, although this is the most common. Many times,...
It is a very bad idea not to appear in court when there is a case against (or for you). If you fail to appear in court when your mandatory appearance is required, you are guilty of a misdemeanor. If...