Designing victims' reparation policies and solving agrarian disputes are fundamental aspects to build peace after a civil conflict. In 2014, a ceasefire with the oldest Latin-American guerrilla took place in Colombia and a peace agreement was signed in 2016. The Land Restitution Policy (LRP) oriented to restore property rights of forcibly displaced victims was one of the peacebuilding and victims' reparation policies. In this paper, we explored the effect of the LRP on violence against social leaders. These actors represent the interests of their communities, oppose the expansion of illicit activities in their territories and are guarantors of informal property rights in most of Colombian rural areas. In this article we determined whether or not a comprehensive intervention, such as the LRP, had community spillover effects in social leaders' exposure to violence. We showed that the LRP significantly reduced the killing of social leaders. Yet, the effect depends on both the intensity of the policy's implementation and its interaction with improved territorial security conditions. Our results suggested a reduced rate of killing of social leaders in municipalities in which LRP was more intense (measured by the number of active processes registered in the program) after the ceasefire with the FARC. In absence of the LRP, after the ceasefire with FARC, the rate of killing of social leaders would have been 1.8 times higher. We explained our findings by an improvement of socioeconomic conditions, an increase in trust within beneficiaries' communities, and the design of a security intelligence mechanism implemented within the policy.