José de los Santos Berreyesa was born in Yerba Buena (present day San Francisco) in northern Alta California of Mexico.
He was the sixth child and fourth son of José de los Reyes Berreyesa.
When his father traveled up to see how his three sons were being treated in jail, the father and two cousins, twin sons of Francisco de Haro, were shot and killed in San Rafael by a group of three men, including Kit Carson, who was assigned the task by Frémont.
[2] Later, Carson told Jasper O'Farrell that he regretted killing the Californios, but that the act was only one such that Frémont ordered him to commit.
[3] Berreyesa received the 17,742-acre (71.80 km2) Mexican land grant of Rancho Mallacomes from Governor Manuel Micheltorena in 1843.