Admissions are an exception to the hearsay rule in Pennsylvania and thus Bucks County. This is contrary to many other states and the Federal Rules of Evidence.
For an admission to be admitted, the statement/admission must have been made by a "party opponent". So, what is a party opponent? Normally, this would be the defendant. Why? Well, the defendant would be available to testify and refute such a statement. As Commonwealth v. Watkins of 2003 allows, a defendant's voluntary pretrial admissions or confessions are admissible as substantive evidence under the admission exception as long as such admissions or confessions comply with constitutional safeguards (i.e. no illegal detention or arrest occurred).
Sometimes, there is a blending of civil and criminal law with the admission exception. For example, say a person gets a DUI in Quakertown and there is an accident involved in the DUI. If they plead guilty in the Bucks County criminal court, their guilty plea can be used as an admission in a civil personal injury suit. But, if a person enters a plea of nolo contendere or withdraws their guilty plea, no admissions occur for a civil suit.