Impunity occurs when legality is undermined. This is a lot of legal injustices occur to individuals. Due process of the law is undermined and in such a circumstance guilty offenders are left to go scot free. Rural homicide was on the rise over the 1990s as the result of the disruption of PRI patronage-client networks caused by rising electro competition.
Before 1994, electoral courts served at the mercy of the status quo authority. They could not punish offenders. In the specific states where the PRD most contested the elections, such as in Michoacán and where the most PRD militants (27%) were killed by 1994, postelectoral legal complaints during the period between 1989 and 1992 were handled by the Michoacán Electoral Commission, an arm of the PRI-controlled state executive (Schatz 2008:265).
This was also the pattern in the states of Guerrero, Hidalgo, and Puebla where a number of the political murders of PRD members also occurred and where state PRI-controlled executive electoral commissions were unable to quell electorally related violence. Nor were those institutions set up to curb state crime in general able to punish offenders (Schatz2008:266).