“No face, no case” is a term that refers to a commonly held belief that if a witness doesn't show up to court the case has to be "dropped". THIS IS NOT ALWAYS TRUE. This comes from an incorrect understanding of the Confrontation Clause in the Constitution. A defendant has a right to confront witnesses, but a defendant may forfeit this right. The forfeiture doctrine was first examined in the 1878 Supreme Court of the United States (SCOTUS) case of Reynolds v. United States. This case involved Reynolds, an accused polygamist, who hid one of his wives to ensure she was not served with a subpoena. The court held that by doing so, Reynolds forfeited his rights under the Confrontation Clause, and the court admitted the wife’s prior testimony into evidence.
The Confrontation Clause means that during a trial a defendant is able to confront witnesses, presently in a courtroom, for the charges being considered. Meaning that previously stated testimony is generally admissible. The SCOTUS stated in Reynolds,
“The Constitution gives the accused the right to a trial at which [s]he should be confronted with the witnesses against him; but if a witness is absent by his own wrongful procurement, [s]he cannot complain if competent evidence is admitted to supply the place of that which he has kept away.”
What if the complaining witness doesn't show? Even if a complaining witness fails to show up to court or trial the State may offer other evidence. If there's video footage of the incident that can almost always be used. 911 phone calls are another form of evidence that can be used without the complaining witness' cooperation. Bodycam footage might be able to be used however recent decisions have limited its admissibility without another witness. At trial, the prosecution can directly examine the police officer who took the complaining witness' statements, and this officer can testify to the relevant portion of said statements.
The bottom line is that the State can use a variety of methods to bring evidence that a crime had been committed even without a complainig witness present. You need an experienced attorney who can guide you through this process and determine the best course of action.