In Criminal Actors in Latin America, Jonathan D. Rosen offers, in 86 pages, a short primer to the complex landscape of criminal actors in Latin America. He examines the nature of major criminal actors in selected countries across the region, ranging from Mexico’s Sinaloa Cartel and El Salvador’s Mara Salvatrucha (MS-13) to Argentina’s The Monkeys (Los Monos). He provides an overview of these groups’ organizational structure, leadership, reach, operational scope, and levels of violence, as well as patterns of fragmentation and, in some cases, the dismantling of key criminal organizations.

The book is organized into six chapters. It consists of an introductory chapter, four case-study chapters covering Mexico, Colombia, El Salvador, Honduras, Brazil, and Argentina, and a concluding chapter. Rosen includes insightful introductions and conclusions within each chapter to guide the reader and synthesize the main contributions. Although he does not state it explicitly, the selection of the six countries appears to reflect their relevance for understanding different types of criminal actors in Latin America. Thus, the four empirical chapters examine some of the major criminal groups and their leaders in the selected countries.

In the introductory chapter, Rosen begins by analyzing how different criminal actors are defined, using the example of whether MS-13 should be classified as a drug cartel or a gang. He emphasizes that politicians most frequently use these terms as synonyms, even though the nature of each criminal group is different. In this chapter, Rosen also highlights several themes that cut across the empirical chapters: criminal groups’ ability to serve as a de facto form of government in certain territories, and governments’ focus on capturing kingpins, which has led to the implosion or fragmentation of criminal organizations. He also discusses the role of the militarization of the war on drugs and the collusion between state authorities and criminal actors.

One of the book’s distinguishing features is its organization. The case-study chapters are divided into sections, each devoted to the examination of a specific criminal group. In general, the analysis begins with the actors with greater reach and longer developmental trajectories and then moves on to those with more local operations or more recent emergence. The chapters highlight the distinct characteristics and operational dynamics of powerful transnational organized crime groups, cartels with regional reach, guerrillas, criminal bands, gangs, and a wide range of other actors operating across the six countries under analysis.

The first two empirical chapters analyze the cases of Mexico and Colombia. In the chapter on Mexico, Rosen traces the evolution of the Sinaloa Cartel, Los Zetas, the Cartel Jalisco New Generation (CJNG), and other criminal organizations. He shows that competition between groups and state pressure tend to produce fragmentation, adaptation, and shifts in power, rather than the definitive disappearance of these organizations. In the chapter on Colombia, he outlines the rise and decline of the Medellín, Cali, and Norte del Valle cartels, and incorporates the criminal dynamics of guerrilla and paramilitary groups, as well as criminal organizations that emerged following demobilization processes.

The two subsequent chapters examine two cases each. The chapters on El Salvador and Honduras explore how the 18th Street (Barrio 18) and MS-13 gangs consolidate power through extortion and territorial control, and how—along with other criminal groups—their relationship with the state varies between repression, negotiation, and co-optation. On the one hand, the chapter on Brazil and Argentina shows that in Brazil the First Capital Command (Primeiro Comando da Capital—PCC) and the Red Command (Comando Vermelho—CV), both born in prison, developed cohesion and discipline that enabled them to extend their influence beyond prison walls as criminal actors with a nationwide presence, capable of corrupting institutions and expanding in a context of impunity and weak institutions. On the other hand, the chapter shows that despite major hits to its leadership, the family-based criminal organization The Monkeys persists through a franchise-like model, fueling territorial disputes and significant security challenges in the city of Rosario, Argentina.

The concluding chapter synthesizes the book’s main lessons. Rosen returns to the debate about how to define organizations such as MS-13 when public officials label them as terrorists, and he stresses that, unlike Al Qaeda or the Islamic State of Iraq and Syria (ISIS), criminal groups pursue primarily economic goals rather than political or ideological ones. He then highlights two central lessons: first, hardline strategies such as military deployments often increase violence; and second, structural problems such as corruption, impunity, and institutional weakness strengthen these groups by facilitating their collusion with the state and undermining long-term solutions. The chapter closes by arguing that, in order to survive, criminal actors will continue to adapt and evolve.

Overall, the book meets its goal of showing that the region is home to multiple criminal groups with diverse profiles and modes of operation. In that sense, its main contribution lies in offering a guided introduction to major criminal actors in six Latin American countries. While the book is aimed at students and readers interested in learning about criminal actors operating in the region, it may also be useful for scholars and policymakers seeking a concise text to understand the common dynamics and key points of variation across cases.

Its limitations, however, stem from the inherent constraints of the format. The book’s brevity reduces the space available to delve more deeply into some criminal actors and to incorporate additional relevant cases. For example, the chapter on Brazil and Argentina—the shortest in the book—devotes six pages to analyzing three criminal groups. Similarly, the chapter on Colombia provides a very brief analysis of the National Liberation Army (Ejército de Liberación Nacional—ELN) and The Invisibles (Los Invisibles). In addition, readers interested in a regional criminal landscape might expect to find the case of Ecuador, but the book does not include it. Although the evolution and reach of criminal groups in Ecuador are more recent and relatively smaller, the rising levels of violence since 2018—reflected in the rise in the intentional homicide rate—makes it a relevant case for future analysis (Dressler and Wolff Reference Dressler and Wolff2024, 270).

Lastly, in line with Rosen’s own caveat in the introduction, the book does not aim to offer an exhaustive analysis of the criminal actors it examines. Rather, it clarifies that each of them could be an entire volume. In doing so, the book opens a research agenda that calls for more in-depth studies of both the actors examined and those left out.