In Oaxaca the penitents gathered…
in front of Preciosa Sangre de Cristo on Good Friday…
preparing for the Procession of Silence.
For those who are wondering, “What’s with the hoods (capirotes)?” The answer can be traced back to the Middle Ages. Members of lay religious charitable organizations (cofradías) would don the masks and hoods to guarantee anonymity and promote humility in their service.
From the Holy Week in Seville, Wikipedia page:
At the heart of Semana Santa are the brotherhoods (Hermandades y Cofradías de Penitencia),[1] associations of Catholic laypersons organized for the purpose of performing public acts of religious observance; in this case, related to the Passion and death of Jesus Christ and to perform public penance.
The brotherhoods, besides the day-to-day work in preparation for the processions, also undertake many other self-regulated religious activities, and charitable and community work. Many brotherhoods maintain their own chapel, while others are attached to a regular parish.
The Spanish brought the tradition to Mexico and penitents continue to play a major role in the Viernes Santo, Procesión del Silencio in Oaxaca.