4.15 Dual Role Testimony is a type of evidence presented in a court of law in which a witness is testifying to two separate roles. This may include acting as both a fact witness and an expert witness, or as a party and a witness in the same case. In some cases, a lawyer may act as both a lawyer for one party and a witness for the other party. There are two main types of 4.15 Dual Role Testimony. The first is a combined role of fact witness and expert witness. In this case, the witness is qualified to give expert opinion testimony based on their expertise or experience in a particular field, as well as testifying as a fact witness to what they personally saw or heard. The second type is a combined role of party and witness. In this case, the witness is a party to the case and is providing evidence on behalf of their party, as well as testifying as a witness to what they personally saw or heard.