A custody action is initiated by someone filing a custody complaint. The complaint is prepared by an attorney and signed by one of the parties seeking custody. A parent, grandparent or even a third party may file for custody. The complaint is filed in the Prothonotary's Office and served on all the parties named in the complaint.
When you are charged with a criminal offense a preliminary hearing is the initial court hearing normally held the magistrate's office where the offense occurred. In Lancaster County certain preliminary hearings are held downtown at the courthouse (DUI's and domestic violence cases). The arresting officer will file the the criminal charges. The District Attorney's Office will prosecute those charges by offering evidence against you. Evidence can take the form of testimony from witnesses, scientific testing, and statements made to the police. A preliminary hearing does not determine guilt or innocence. Instead, the purpose of a preliminary hearing is to determine whether there is enough evidence for the case to move forward. If so, the case will move downtown to "big court". If they can not, your attorney can make a motion to dismiss. At that point the case may be over for good. But not always.