In the case to which I have last adverted, and in some others which came under my observation, I attribute the failure of justice to the ignorance and consequent incapacity of members of the police force or of the constabulary engaged. However, I consider it only just to remark on the paucity of instruction afforded to constables for detective purposes. Activity of body, corporeal strength, general mental intelligence, and moderate educational acquirements, are considered sufficient qualifications for the discharge of detective duties, and further teaching is left to be acquired by future experience. In several continental states, reports of important criminal trials are arranged for the use of the police by an _archiviste_, and instruction is thereby afforded as to the means by which guilt was established, or, perhaps, to the mistakes or rash precipitancy by which justice was defeated, or innocence accused. The essential difference between our police and that which I have observed in France, Belgium, and Rhenish Prussia, is exhibited in the speedy arrests of suspected persons here, compared with the tardiness of apprehension in the latter countries, unless the prisoner is actually caught _in flagrante delicto_. The moment that a suspicion is entertained in Ireland, the supposed delinquent is seized, and thereby all chance of obtaining evidence by his subsequent acts is completely lost. The foreign system is to watch him night and day. This frequently eventuates in detecting him concealing property, weapons, or bloodstained clothes, or suddenly quitting his abode without any previous intimation, and perhaps under an assumed name. If we are to have an efficient police, we will find it indispensably necessary to keep well-informed, shrewd, patient, watchful detectives. I have known many who contended that a constable should adopt no disguise, but that, in the uniform of the force to which he belongs, he should perambulate the streets, suppress disorders, apprehend offenders, and when directed to execute warrants, he should go in search of the culprit openly and avowedly. To such I would suggest, that if in the organization of a police there is anything unconstitutional, it is rather to be found in the adoption of a uniform than in the attire of "plain clothes." The old common-law constable had no uniform; he went, and came, and mixed amongst other men, without a number on his collar or a crown on his buttons, and still his office and its functions were not denounced as unconstitutional. A policeman in uniform may patrol our streets, suppress riots, restrain indecency, and apprehend the pickpocket or drunkard; but it is not by such that the progress of the swindler is to be traced and stopped, the haunts of the burglar ascertained, or that the minute circumstances, trifling to the casual observer, but amounting, in the aggregate, to perfect conviction, are to be discovered and concatenated to establish the fearful guilt of the murderer.