On 8 September 1890, in the rural town of Utuado in Puerto Rico, for reasons that were never ascertained, 28-year-old Esteban Serrano Borrero and his 40-year-old neighbour Faustino Santos Nazario, both jíbaros or mountain peasants, came to blows. Santos was later found dead, and Serrano arrested and brought to trial. This mundane occurrence in the far reaches of what remained of the Spanish Empire would become an early test of the clash between modern European notions of justice and lingering traditions of colonial authoritarianism. At that time, it should be remembered, Puerto Rico was still a Spanish territory – one that had long been fighting to transcend the status of colony and attain that of full-blown province. After much delay in extending constitutional rights to the Antilles, the Spanish Penal Code of 1870 was modified for use in Puerto Rico and Cuba in 1879; the 1882 Ley de Enjuiciamiento Criminal was also applied in 1888. It was thus that Serrano Borrero's case came before the newly created Audiencia Criminal de Mayagüez.

According to details that emerged during the proceedings, a handful of people arrived after the fight had started and saw Serrano strike Santos with his hands and knees, eventually knocking him down despite his greater size. Santos's wife and a couple of others separated the two men, and the woman later testified that she took her husband

Later that evening, Serrano Borrero approached Andújar's house on friendly terms, looking for one of the latter's sons.