R (Aboro) v Secretary of State for the Home Department [2018] EWHC 1436 (Admin) is an unlawful detention claim about how conflicting psychiatric evidence should be interpreted. The Secretary of State relied upon the evidence of a detention centre doctor, in preference to experts instructed by Mr Aboro, to justify the view that his mental health problems could be satisfactorily managed in detention.

The High Court ruled that she was entitled to prefer the evidence of the clinician responsible for treating Mr Aboro because that doctor had greater access to him in detention. The upshot, in terms of the specific case, was that although the unlawful detention claim technically succeeded on that basis that the Secretary of State had not considered the application of her own policy to the detention of vulnerable people, this declaration only yielded nominal damages because he would have been detained anyway.

More broadly this case demonstrates how difficult it is, when the Home Secretary has custody of the individual, to compile evidence refuting his view that detention is lawful.

Mr Aboro was detained from 6 August 2012 until 23 September 2013 and alleged that most of this detention was unlawful. He instructed a psychiatric expert who reported that he was suffering from a severe depressive disorder which could not be managed in detention. The Home Secretary obtained evidence from a psychiatrist at the detention centre which disagreed with this diagnosis.

At that time the Home Secretary’s policy was that people suffering from mental illness should only be detained if their condition could be satisfactorily managed in detention. The substance of the policy has now changed, but that does not diminish the relevance of this case to how the Home Secretary should approach conflicting evidence when deciding whether to maintain detention.

Karen Steyn QC, sitting as a deputy High Court judge, ruled that Mr Aboro had been unlawfully detained due to the failure to consider the relevant policy:

There is nothing to suggest that those making the decisions to maintain the Claimant’s detention addressed their minds to §55.10 of the policy. There is no evidence that they asked themselves whether the Claimant was suffering from a serious mental illness which could not be satisfactorily managed in detention. Consequently, in my judgment, the decisions to maintain the Claimant’s detention were procedurally flawed, rendering the Claimant’s detention from 23 September 2012 until his release unlawful.

Public law errors such as this only lead to nominal damages unless the claimant can also show that they would not have been detained but for the error. Unfortunately, the judge held that it would have been open to the Home Secretary to make a lawful decision to detain Mr Aboro under the policy:

I have no doubt that, if the Secretary of State had addressed the question whether the Claimant was suffering from a serious mental illness which could not be satisfactorily managed in detention, it would have been open to her, acting reasonably, to give the answer: “no”.

Dr Sultan was the principal responsible clinician when the Claimant was in Colnbrook IRC and he had extensive contact with the Claimant. Dr Sultan consistently advised the Secretary of State that the Claimant was fit to be detained. I agree with Professor Maden that in initially advising that the Claimant was not fit to fly, following his first assessment, Dr Sultan made a “humane, sensible and cautious decision about a man with whom he had only brief acquaintance”.

The judgment placed much emphasis on the fact that the Home  Secretary’s expert was the doctor “on the spot” at the detention centre and therefore had better access to the claimant.

This is troubling because the asymmetric level of access to Mr Aboro was the product of the Home Secretary’s decision to detain him, which is exactly what Mr Aboro was seeking to challenge in this claim. There is a risk that by preferring the evidence provided by the detention centre doctor the judge has allowed the Home Secretary to insulate his decision from challenge through the conditions of custody, which prevent other doctors from seeing detainees as frequently as those employed at the detention centre.