What do tattoos symbolize in the novel, American Dirt?

Tattoos mark cartel members and are symbolic of danger and death. Luca astutely notices Lorenzo's tattoo early on and is aware that the tattoo symbolizes violence. The tattoo is of a sickle with blood dripping from its tip. The drops of blood that drip from the sickle indicate the number of kills Lorenzo has made. Each time the tattoo on Lorenzo's leg reveals itself, it foreshadows impending violence.