If a probation/parole-violation case goes to trial, the accuracy of the offender's tracking device may be questioned. The "Practical Guide for Offender Tracking Evidence Protocols" (The Guide) recommends procedures for managing four types of tracking evidence most likely to be required for a court proceeding. The four types of evidence are physical evidence, electronic evidence, documentary evidence, and oral testimony. The most common physical evidence in tracking cases are tracking devices, straps, and other attaching components. Electronic evidence pertains to the accuracy of the tracking device at issue in the case. Documentary evidence consists of photographs and written material, including items that identify the person who placed the monitor on the defendant; strap and equipment settings; placement of equipment; inspection dates; conditions of tamper-evidence components; recording of statements concerning a violation or crime; post-removal testing procedures; and photographs of tamper indicators. Oral testimony in such cases refers to any words spoken by a sworn witness. The major concern in such testimony is that it be accurate and does not exceed the scope of the witness' level of competency. For each of the four types of evidence, the Guide focuses on an agency's development of protocols and procedures that maximize the value of the evidence.