What burden of proof is required for subject-defeating surveillance under target specific orders?

The appropriate burden of proof for subject-defeating surveillance under target-specific orders is indeed probable cause. This standard requires that there is a reasonable belief, based on facts or evidence, that a crime has been committed or that the target of the surveillance is involved in criminal activity. Probable cause is a higher threshold than reasonable suspicion, which is based more on a reasonable belief without the need for substantial evidence.

In the context of wiretap laws, establishing probable cause is essential because it protects individual privacy rights while ensuring that law enforcement has sufficient justification for conducting surveillance. This requirement is a safeguard to prevent potential abuse of surveillance authority.

The other burdens of proof mentioned, such as clear and convincing evidence and preponderance of evidence, are used in different legal contexts. Clear and convincing evidence is often applied in civil cases, while preponderance of evidence is a lower threshold used primarily in civil litigation, where the evidence just needs to show that something is more likely true than not. Neither standard would meet the stringent requirements necessary for initiating intrusive surveillance measures like wiretapping.