themselves.35 Although not all system crimes relate to patterns of events, the investigation of patterns can be crucial in determining the responsibility of those behind the scenes. This issue is particularly important in situations where responsibility may be based on omission, rather than commission. Reconstructing patterns can help build a framework that implies that those behind the scenes knew or had reason to know that the events were occurring or were likely to occur and failed in their duty to prevent them. There are further compelling reasons to conjoin cases involving similar acts: • J udicial economy. As a matter of economy and prudent use of resources, it is much more efficient to group cases for the purposes of investigation and trial than to deal with each one individually. • Efficiency. Apart from the simple but expensive issue of court time, an atomistic approach will inevitably lead to a huge duplication of efforts of investigators and prosecutors on several aspects of the multidisciplinary investigation. • Security. A long series of individualized trials dealing with very limited subject matter isolates witnesses, lawyers and judges. The longer the process takes, the more costly it is to maintain the necessary levels of protection of all those involved. • Potential for impact. Long, drawn-out trials on very restricted incidents ignore the important opportunity to present cases in a way that describes to the public the real nature of the events as they happened—as part of a systematic attack organized at a high level.36 • L egal requirements. If trials seek to deal with certain international crimes, demonstrating patterns will also be a legal requirement. 4. A proposed model for investigations The following is a possible structure of investigations and prosecutions.37 A dedicated multidisciplinary unit should be established to address serious crimes. Various models of such ap- 35 F or example, the kinds of massacres the army committed in the Guatemalan civil war required considerable strategic organization, including surrounding villages, controlling exits and entrances, torturing and murdering unarmed civilians, and destroying houses and livestock. Several incidents carried out in limited geographical areas suggest knowledge and control on the part of regional commanders and possibly even at the level of the high command. For an excellent explanation of the potential significance of patterns, see Fenrick, loc. cit. It is not possible to say with certainty how many specific acts must be included in the proof of a pattern to establish knowledge and control. The more information on planning and organization, the less will be needed in terms of acts showing frequency, modus operandi and location. In the final analysis, the art of investigation is finding the correct balance of all the elements. 36  ne of the architects of the trials in Argentina has noted that it was the very drama of the trials, describing the abusive system O in question, that played such an important role in helping to restore the rule of law and respect for the administration of justice. Carlos Santiago Nino, Radical Evil on Trial (New Haven, Yale University Press, 1996), pp. 132–134. 37 It follows, to a large extent, the model adopted by the Special Prosecutor in Mexico. This is one of the strongest aspects of those efforts in that country, although the practical results are not ideal. Most of the difficulties related to a lack of resources in some teams or to a lack of appropriate training in others. The model also borrows heavily from the experience of the ICTY Office of the Prosecutor, especially in the central role of analysis. However, ICTY has not been very successful in creating suitable mechanisms to ensure the meaningful participation of victims. 16