The role of monks and their appellation in 18th century?

A public execution took place in Toulouse, in an officially Catholic state, in the 18th century, France. A Protestant father, Jean Calas, was sentenced to death on the ground that he had murdered his son who turned a Catholic. I have a question about the words, a monk and a Father, in a description of Adam Smith who witnessed this execution (See the bottom of this thread). **First**, a monk usually lives in a monastery he belongs to and remains there for doing meditation or exercise together with other monks. I am aware that there are two types of monks: choir ones who are ordained, and lay /claustral brothers who are not ordained. Can a choir monk leave his monastery and take part in a public execution to hear the last confession from an inmate? **Second**, can a choir monk be eligible to be called Father as a qualified priest? Is there any other specific appellation than Father when you call a choir monk? **Third**, there is an image depicting this execution where a monk or a friar wears reddish-brown monastic dress with a large white cross on his chest. The image comes from the frontispiece of a chapbook published in England soon after the execution. Voltaire also wrote about the Calas affair, disclosing the specific names of the priests attending the execution: “Father Bourges, a Dominican and a professor of divinity, together with Father Caldagues, a priest of the same order, were appointed to assist him [Calas] in his last moments.” The colour of the Dominican robe is usually all white, but is there a type of Dominican robe depicted in the image? Is it a sheer fictional robe invented by an Englishman? ****************** After he had been broke, and when just going to be thrown into the fire, the monk, who attended the execution exhorted him to confess the crime for which he had been condemned. My father, said Calas, can you bring yourself to believe that I was guilty? [III.2.11] Adam Smith, The Theory of Moral Sentiments (Oxford: Oxford University Press, 2014) 120.