Interpretation of recorded 911 calls can be very challenging even for those who use two-way communications on a daily basis. Every time a 911 call is made are recorded by magnetic tape, compact disc, or in an electronic format.

The attorney who wants to hear the 911 call should request the “raw voice data” in its entirety to include 10-15 minutes before and after the incident. Some agencies will unintentionally provide only the transmissions from that incident and leave out important background noise.

Background noise is any background sound, tone, voice etc. being transmitted on the same frequency as the ongoing incident. Background noise reduces the audio intelligibility and clarity of the two-way radio transmission.

Background noise is important to preserve because it can indicate and document vital information. Background noise places a “marker” on the recording, which can then be verified from other and sometimes multiple audio sources.

For example, a field unit member contacts the dispatcher and reports the helicopter has landed (landing marker). The dispatcher places a time to this event as occurring (time marker) and acknowledges the field unit (unit marker).

This same information can be confirmed when the attorney listens to the recordings of the helicopter communication. The helicopter pilot reports to the dispatcher the helicopter has landed (landing marker). The helicopter dispatcher acknowledges the helicopter landing (landing mark) and places a time to this event as occurring (time marker). These markers are compared for accuracy and consistency to support or contest the events of the incident and allegations.

This data, along with the medical record, helps to reconstruct the timeline of events. A legal nurse consultant may assist the attorney inputting all of the data together to determine what happened when.

1. The technological devices that may contain information to confirm or deny allegations involved in a case.
2. What information these technological devices retain.

Med League provides medical expert witnesses to trial lawyers. Please call us at (908)788-8227 or contact us today to discuss your next case.