# Reliability & Accuracy of 'Expert' Witnesses

**URL:** <https://forum.mentalhealthlaw.co.uk/t/reliability-accuracy-of-expert-witnesses/265>\
**Category:** Mental Health Act\
**Tags:** moj\
**Created:** [9 December 2020 15:02 UTC](https://forum.mentalhealthlaw.co.uk/t/reliability-accuracy-of-expert-witnesses/265 "2020-12-09T15:02:44Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Joolsleeds](https://forum.mentalhealthlaw.co.uk/user_avatar/forum.mentalhealthlaw.co.uk/joolsleeds/32/56_2.png) [@Joolsleeds](https://forum.mentalhealthlaw.co.uk/u/Joolsleeds)\
**Post date:** [9 December 2020 15:02 UTC](https://forum.mentalhealthlaw.co.uk/t/reliability-accuracy-of-expert-witnesses/265/1 "2020-12-09T15:02:45Z")

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I’m concerned about the accuracy and reliability of some of the ‘expert’ psychiatric evidence given in some recent cases.

In the recent [R v Nelson [2020] EWCA Crim 1615](https://www.mentalhealthlaw.co.uk/R_v_Nelson_(2020)_EWCA_Crim_1615) case dealing with Sec 45a - Paragraph 39 says:

\*_"Dr Cumming gave evidence that those released under section 37 and 41 MHA hospital and restriction orders were likely to reoffend in 4 per cent of cases.”_

This is er, questionable.

Recent academic evidence shows a very high rate of recidivism by restricted patents. A [long-term study](http://www.hundredfamilies.org/wp/wp-content/uploads/2020/02/Westhead-et-al-2018-MSU-Reconviction-.pdf) of patients released from Arnold Lodge medium secure unit in Leicester found 48% (368 patients) were re-convicted after release, 30% (109 patients) for grave offences.

Another study of [patients released from high secure](https://academic.oup.com/bjc/article/44/5/783/464704) psychiatric hospitals found 38% were re-convicted, 26% for serious offences.

And not all offending results in conviction, as these types of offenders are often recalled or diverted away from the criminal justice system. Offending rates by restricted patients will be significantly higher than convictions alone suggest.

A further [study of offenders with schizophrenia  
released](https://www.tandfonline.com/doi/abs/10.1080/09585189908402140) from medium secure psychiatric unit in South East London found two thirds of the total – 67% -reoffended violently.

Dr Cummings figures may come from the [MoJ stats 2010-2016](https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/751112/Annex_A_Proven_reoffending_for_restricted_patients_2010-2016.pdf), which claim a re-offending rate of 5.7%, but only counts offending during the first year of release. The MoJ report itself says their figures must be treated with caution.

This is not the first incident I’m aware of where judges have been given partial or inaccurate information by ‘expert’ witnesses. (One thought recently the Home Secretary was involved in the release of restricted patients).

How can Judges ensure they are being given accurate  
and reliable information?

Is there a mechanism to notify them after the fact when this has happened?

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**Author:** ![Jonathan](https://forum.mentalhealthlaw.co.uk/user_avatar/forum.mentalhealthlaw.co.uk/jonathan/32/88_2.png) [@Jonathan](https://forum.mentalhealthlaw.co.uk/u/Jonathan)\
**Post date:** [10 December 2020 14:13 UTC](https://forum.mentalhealthlaw.co.uk/t/reliability-accuracy-of-expert-witnesses/265/2 "2020-12-10T14:13:18Z")

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The full paragraph from that case is:

> Dr Cumming gave evidence that those released under section 37 and 41 MHA hospital and restriction orders were likely to reoffend in 4 per cent of cases. By way of comparison Dr Cumming said that 28 per cent of those released under life licences would reoffend, although there was no exploration in the evidence of what was meant by life licences.

(The final sentence is confusing as, unless there is more to it than I realise, they must know what’s meant by life licences. Maybe the judge meant there was no exploration of the type reoffending, how soon after release, etc.)

The Parole Board’s Twitter account [said this today](https://twitter.com/parole_board/status/1337002952888868867):

> The overwhelming majority of people released by the Parole Board are safely managed in the community. Just 0.5% of prisoners we release are convicted of a serious further offence.

It would be good to see where all these statistics come from and what definitions are used.

> [@Joolsleeds](#):
>
> How can Judges ensure they are being given accurate  
> and reliable information?
> 
> Is there a mechanism to notify them after the fact when this has happened?

I don’t know, but you’d imagine the CPS conducts internal training on mental health disposals. Maybe you could ask to be involved in that, with the aim of ensuring that the barristers instructed have sufficient knowledge to avoid the Court of Appeal being presented with inaccurate information. There are various aspects of this and other judgments that reveal misunderstandings.

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**Author:** ![jonesrm](https://forum.mentalhealthlaw.co.uk/letter_avatar_proxy/v4/letter/j/46a35a/32.png) [@jonesrm](https://forum.mentalhealthlaw.co.uk/u/jonesrm)\
**Post date:** [11 December 2020 09:34 UTC](https://forum.mentalhealthlaw.co.uk/t/reliability-accuracy-of-expert-witnesses/265/3 "2020-12-11T09:34:42Z")

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“Serious doubt” has been expressed about the expert evidence of suicide risk provided to the Supreme Court in [Rabone v Pennine Care NHS Foundation Trust [2012] UKSC 2](https://www.mentalhealthlaw.co.uk/Rabone_v_Pennine_Care_NHS_Foundation_Trust_(2012)_UKSC_2,_(2012)_MHLO_6): see [“Rabone and four unresolved problems in mental health law”, The Psychiatrist (2013), 37, 297-301](https://www.mentalhealthlaw.co.uk/George_Szmukler,_Genevra_Richardson_and_Gareth_Owen,_%27%E2%80%9CRabone%E2%80%9D_and_Four_Unresolved_Problems_in_Mental_Health_Law%27_(2013)_37_The_Psychiatrist_297).

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**Author:** ![Joolsleeds](https://forum.mentalhealthlaw.co.uk/user_avatar/forum.mentalhealthlaw.co.uk/joolsleeds/32/56_2.png) [@Joolsleeds](https://forum.mentalhealthlaw.co.uk/u/Joolsleeds)\
**Post date:** [11 December 2020 10:24 UTC](https://forum.mentalhealthlaw.co.uk/t/reliability-accuracy-of-expert-witnesses/265/4 "2020-12-11T10:24:52Z")

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Thanks will read with interest - the full article is [here](https://www.cambridge.org/core/services/aop-cambridge-core/content/view/10D4EE60DD29F1F1755C7325497B7CC4/S1758320900003966a.pdf/rabone-and-four-unresolved-problems-in-mental-health-law.pdf)
