That is conceded, assuming that we are going to broaden the question by introducing a new element here - that of the expert accident reconstruction witnesses.
Not required. One does not need reconstruction experience or training to offer a professional opinion as to the CAUSE of a collision.
However, even in those jurisdictions where causal opinions by qualified experts are allowed, the opinion as to the cause or contributing causes of the accident must be based solely upon the witness own investigation unaided by the hearsay statements of witnesses taken at the scene.
Not entirely so out here as statements of witnesses can be part of the investigation and assist in determine the facts - especially when the statements do not conflict and the facts at the scene support those statements.
The determination of cause can largely be determined based upon the physical evidence at the scene absent the statements of witnesses. Sometimes, however, witnesses might play an integral role in the investigation - especially when the cause might be indicated as a failure to stop at a red light.
A case in point (a vehicle/pedestrian /cross walk – fatal accident) is NENO v. CLINTON , New Jersey Supreme Court, 16 N. J. 573 Decided May 16, 2001.
In the trial court, the officer was permitted to testify that in his opinion the negligence of the pedestrian was the cause of the accident because he had entered the intersection against the traffic signal.
The reviewing court threw out that opinion testimony as being inadmissible. The reason being that it was not based solely upon the expert’s investigation, but gathered with the aid of the statements of witness at the scene.
I understand the reasoning, but the OP is in CA not NJ. Though, out here, stepping into the intersection against the light would not automatically make a person at fault for the collision as drivers are also required to exercise due care. So, depending on the facts, it might not matter whether the pedestrian stepped into the street against the light or not.
And, the court is certainly within its right to dismiss the opinion if it feels inclined to do so.
That is, the California Highway Patrolman investigating the intersection accident – qualified expert or no – would not be permitted to voice the opinion that: “THE PRIMARY CAUSE OF THE ACCIDENT WAS THE VEHICLE THAT FAILED TO STOP” . . . if that opinion was based upon hearsay statements.
If SOLELY based upon statements, perhaps. But, I cannot imagine the investigating officer based his or her investigation SOLELY on witness statements. Though the witnesses could be brought in to state what they saw, and the officer could then supplement it with his investigation and the court could render an opinion based on all the testimony.
And unless the officer observed the accident, he would not be able to determine which vehicle had the right-of-way, short of relying on hearsay statements.
Yes, you very often can ... there are a number of ways to do so.
Nor should the officer be permitted to testify that the failure to be “buckled up” was the cause of the deceased occupant’s demise. There are instances (rare) where fatal traffic injuries have been avoided merely because a seat belt was not worn at the time.
I doubt that the officer wrote that. If he did, he may have opined that a contributing factor was the lack of wearing a seatbelt, or, perhaps the M.E. made such a conclusion that was included in the report or a supplement. We don't know. No matter, the officer would never be allowed to testify as to the actual cause of death.
Here are the requirements in CA:
http://leginfo.ca.gov/cgi-bin/displaycode?section=evid&group=00001-01000&file=800-805
As a note, I have testified as an expert in numerous collision investigations and I will not have the Reconstruction course until May. And, yes, my conclusions are sometimes based in part upon witness statements and my testimony clearly reflects those positions. As stated in the law, that witness "may be called and examined by any adverse party as if under cross-examination concerning the opinion or statement." To avoid that, the witness has typically been presented by the state prior to my testimony to lay that foundation.
Ultimately the court can accept or reject the testimony as it sees fit. I have never had my testimony dismissed or objected to, but I suppose there is always a first time.
