A client has legal rights against a retained attorney for the negligent handling of his claim. The plaintiff must prove that the outcome of his claim or case would have had a different result if the attorney had not acted negligently. For example, this would be true if a filing deadline was missed, resulting in the dismissal of the case. It might also involve a claim that an attorney made an error in court that harmed the client. This could require the plaintiff in the malpractice action to retry the prior case as part of the legal malpractice lawsuit.
An action for legal malpractice might also be brought by someone other than the client. For example, if an attorney improperly drafts a client's will, the heirs suffer harm and would therefore have enforceable rights.
You should retain a Southern California legal malpractice attorney with experience handling this type of claim.