- 16 The sheer number of allegations of ill-treatment by the police and their consistency as regards both the types of ill-treatment inflicted and the categories of detained persons to whom they are applied are striking. These factors are alone sufficient to give rise to concern as regards the treatment received by persons detained by the police. That concern is reinforced by the findings of medical members of the CPT's delegation and by the on-site observations made in the course of certain visits. To this must be added a number of weaknesses noted in the area of formal safeguards against ill-treatment (notification of custody to a third party, access to a lawyer, etc.). In the light of all the information at its disposal, the CPT has been led to conclude that certain categories of persons deprived of their liberty by the police in Greece (in particular, persons arrested for drug-related offences; persons arrested for serious crimes such as murder, rape, robbery, etc.) run a significant risk of being ill-treated, and that on occasion resort might be had to methods of severe ill-treatment/torture. 26. The CPT is nevertheless grateful to the Greek authorities for the promptness with which they acted upon its delegation's request to carry out an inquiry into the interrogation methods employed at Athens and Thessaloniki Police Headquarters. Irrespective of the conclusions reached, the Committee considers that the very carrying out of such an investigation might have had a salutary effect. 27. Later in this report, the CPT will recommend some reinforcements of formal safeguards against the ill-treatment of persons detained by the police (see paragraphs 34 et seq.). However, it should be emphasised that legal and other technical safeguards - while important - will never be sufficient; the best possible guarantee against ill-treatment is for its use to be unequivocally rejected by police officers. It follows that the provision of suitable education on human rights questions and of adequate professional training is an absolutely essential component of any strategy for the prevention of ill-treatment. 28. The above-mentioned education and professional training should be pursued at all levels of the police force, and should be ongoing. It should seek to put across and develop two points. First, that all forms of ill-treatment are an affront to human dignity and as such are incompatible with the values enshrined in the Greek Constitution as well as in many international instruments ratified by and binding upon Greece. Second, that resort to ill-treatment is a fundamentally flawed method of obtaining reliable evidence for combatting crime. More advanced interrogation and investigation techniques will lead to better results from a security standpoint. The CPT welcomes the fact that both these points are also emphasised by the Ministry of Public Order in its previously-mentioned report. Further, particular attention should be given to training in the art of handling, and more especially of speaking to, persons in police custody i.e. interpersonal communication skills. The possession of such skills will often enable police officers to defuse situations which might otherwise become violent.