Qualifications of an "Expert"

[Rudiger]

I have read numerous topics where you say you will need an "expert" witness. I would just like some qualification regarding "expert".

I will be defending a Pro Laser III matter later this year. Obviously I dispute the veracity of the speed alleged for various reasons.

I am an ex Victorian Traffic policeman as was qualified in Doppler Radar and heand held Laser and was also an instructor for both devices. I also hold a degree in Traffic Engineering and have given qualified expert advice with regard to vehicular movements both pre and post impact (in collision matters) in the Coroners, Magistrates, County and Supreme Courts. All of my evidence was accepted. I also gave expert evidence in relation to speed estimations.

In this matter the Informants evidence is flawed and the setup and use is questionable. There was another vehicle 50 metres in front of me and the informant was extremely close to the road so both vehicles would have been with in his view, especially 300 metres away.

I have also read how his evidence of "expert" estimation is rarely successfully questioned yet if I quiz him about Doppler Shift together with not knowing speed over distance, or the affects of heavy shadowing, I will run rings around him.

So to sum up, what is your definition of "Expert" witness, and given my experience, do I qualify, in your eyes?

I thank you for your time.

[Hardy]

if I quiz him about Doppler Shift

Lasers don't work on Doppler shift, so my guess is that even if the court accepts you are suitably qualified to give opinion evidence the court is unlikely to accept your opinion!

An expert is anyone who is qualified to give an opinion. You might be qualified to give an opinion if you can satisfy the court that you are suitably experienced educated or trained in the relevant field to have a useful opinion.

[Rudiger]

Hi. Thanks for that. I know lasers dont work on that. What I was referring too re doppler shift was with regard to estimation.

Colour is to light as pitch is to sound. In other words, and I have studied this as part of my degree, red light waves are longer and hit the eye differently to blue light waves. That is why red cars look to be tavelling quicker as they approach. It is relevant because, during trainging for both radar and laser, I always educated my students as to the difference. It is an important technical aspect of nboth speed measuring and of estimation. Especially estimation. It is a visual thing and if you are totally unaware of the difference color has on the ey you cannot hope to estimate correctly. I have tested this as part of my training and during my working life.

The same is said for heavy shaddowing across the road. The movement of the vehicle is exasserbated (excuse spelling) byt shadows and again, this needs to be factored in and mentioned (it should be ) in informant statements.

This is allpractical stuff I used over a period of 16 years as a traffic policeman, yet no one, and I mean not even Mr. Brendan Murphy who I often went up against, ever questioned me about it which I found absolutely staggering.

If you are going to estimate speed and give so called qualified expert evidence as such then that expert evidence than then be tested. These are the tests that should be presented.

An estimate is defined as a guess. Do we really want untested guesses to proive guilt or innocence?

But my original point ios, I was reffering to estimation with regard to doppler.

[rustyone]

strange i was lead to beleave that Laser Doppler Anemometry (LDA), is the technique of using the Doppler shift in a laser beam to measure velocity

[Rudiger]

Any change in frequency due to a moving object can be called Doppler Rust and you may be right. I was using to refer to color or doppler shift.

[Hardy]

A pro laser III does not care if there is any Doppler shift in the wavelength. It measures the time taken for a wave to reflect and from that calculates distance to the vehicle, and by doing that more than once it can calculate change in distance/change in time.

Most lawyers are not too interested in attacking the police estimates. Everyone already knows they are simply self-serving statements which are not subject to any independent assessment or peer review. Funny how a member can get a certificate to show he can turn on and aim a radar but can't get one that shows how accurate his estimates are! It is absurd to expect any person making an estimate of speed to make adjustments to their opinion depending on what colour the car is or whether the sun was shining. Once you get an acknowledgement that an estimation is nothing more than a guess which is not backed up with any empirical testing you don't need to worry about colors and shadows.

[Rudiger]

We can go back and fourth for ever and thats pointless.

I am busy the rest of the week but will call next week and arrange a conference and we can discuss my options then.

Matter has been adjourned for hearing in November due to my poor health and I expect it will be adjourned again on that date as my treatment is ongoing. But this is hanging over my head and not helping my health issues so I want it done and dusted. But the spectre of losing is my main concern and it shouldn't be.

I will cal your office on Monday to arrange.

Cheers.