Final answer:
Witness testimony is typically included as a response to incidents of domestic violence, such as in Catherine Smith's case.
Step-by-step explanation:
In the context of Catherine Smith's domestic violence case, the legal element that is typically included as a response to the incident is Witness testimony. Witness testimony is when individuals who have observed or have knowledge of the incident provide their statements under oath and testify in court. These witnesses can include the victim, other individuals present during the incident, or professionals like police officers or medical personnel.