Radar Gun Follies

[streaky]

Whilst this (taken from a Risks Forum) refers to radar, there might be some value in regards to laser guns.

"
In point of fact, even when a radar gun is working *correctly*, it is fairly easy to cast doubt upon its efficacy.

The typical 'beat a ticket' tract on the Internet includes a lengthy section on questions to ask in cross-examination to throw doubt upon the radar reading. How well was the officer trained, when was the unit calibrated, and so forth.

A typical such document can be found here: www.jesbeard.com/29ab.htm and makes interesting reading.

One noteworthy quote comes from Section 9 on Cross-examinations:

'NOTE: While it probably should become painfully obvious to both the officer and the court that he is simply unqualified to use a radar gun or to or testify regarding its use ... the reality is that the officer and the judge are both likely to think the radar gun is just a magic gizmo you simply point and shoot.'
"

Streaky

[jeffreyarcher]

streaky said:

...the reality is that the officer and the judge are both likely to think the radar gun is just a magic gizmo you simply point and shoot.'

And when the manufacturer provides a so-called expert (who knows sod all about radar, lasers or electronics) witness who says that it is, they certainly will.

[Dwight VanDriver]

jeffreyarcher said:

streaky said: ...the reality is that the officer and the judge are both likely to think the radar gun is just a magic gizmo you simply point and shoot.' And when the manufacturer provides a so-called expert (who knows sod all about radar, lasers or electronics) witness who says that it is, they certainly will.

..... and said Expert lands the Court with a Bill for his testimony that is a months pay packet which is passed to you on G verdict..... makes you think?

DVD

[streaky]

jeffreyarcher said:

streaky said: ...the reality is that the officer and the judge are both likely to think the radar gun is just a magic gizmo you simply point and shoot.' And when the manufacturer provides a so-called expert (who knows sod all about radar, lasers or electronics) witness who says that it is, they certainly will.

And as you will know, if the expert witnesses do not agree, things can get "interesting" (I've been there ... and our side won!). One of the most dangerous things for an expert witness is to be drawn into an attack on the competence of the other side's experts. I've always tried to agree with the other side's expert what terms we will use and how we will explain those to the magistrates/jury and judge. On one occasion (a "computer-assisted" fraud) the prosecution's expert was a young and inexperienced "techie" who was not (IMHO) well advised by his side's legal team. He refused to meet with me beforehand (for those not in the know, experts are supposed to give non-partisan testimony and can talk to each-other to agree descriptions, etc. ... indeed where complex technical issues are involved we are encouraged to talk to each-other. We can also sit in court even before we are called) and in court gave such a biased and inaccurate account of what happened "in the machine" that I was forced to explain the process all over again in detail and quite at variance to his explanation. The judge asked for him to be recalled (he was supposed to be the in-house expert) and questioned him himself. When he admitted that he had never actually examined the processes, but had relied on notes left by the system's designers, the judge recessed and called both legal teams and me (deliberately excluding the prosecution's "expert") to his chambers. Five minutes later we were back in court ... case dismissed (with some harsh words from the judge to the prosecution).

Of course, "your" expert doesn't need to be better than "their's", they just need to be more believable and that comes from clear explanation of the process and the range of error conditions and states that can occur.

Mind you, Sir Robert Watson Watt was unable to defend himself against a charge of speeding when clocked by a radar-gun. Which gave rise to the self-written ode:

Pity Sir Robert Watson Watt,
Strange target of his radar plot,
And thus, with others I could mention,
A victim of his own invention.

Streaky

[g_attrill]

Expert witnesses are still a huge problem in the UK - it is difficult to challenge the "expertness" of one in court.

The Operation Ore cases were quite interesting - the police used some people that were viewed by other experts to be of dubious quality. Jim Bates, who is undoubtledly a genuine expert (he developed the software for the police that is used by other genuine experts). His site has some interesting commentary on specific cases he has worked on, including the defence of Det. Brian Stevens (Soham officer, Ore suspect):

www.computer-investigations.com/reports/case06.html

www.computer-investigations.com/saga.html
www.computer-investigations.com/vogon2.html

Gareth