I have also read that at the last Mass he said before being arrested, people saw him levitate and go briefly into ecstasy.
Also that he asked some nuns to pray that he would be martyred because he said that was his only hope of getting to Heaven. I always wonder why saints would say things like that, as it seems to go beyond just humility, but I need to read the entire biography on him, maybe it explains, or maybe he was being a little bit jokey.
I learned about him by reading a biography of him that was written for tweens, back in the 1970s. My hometown church was doing Adoration then (shortly thereafter they stopped doing it for about 30 years and only recently started doing it again the last few years) and my mother had a regular hour and would take me. I was about 12 and didn’t really understand Adoration and had trouble sitting silently for a whole hour so I would look for something to read, since I liked to read, and someone had left off this book about Fr. Pro. I was quite horrified to read about the whole Cristiada because I had never heard of it prior to that point and it was only about 50 years ago then. It described how Fr. Pro had all these disguises he used to evade the police. And how when he and the dictator Calles were both dead and buried, nobody bothered to visit Calles’ big tomb, but everybody went to visit and pray at Fr. Pro’s grave.
It would have been nice if the religion classes back then had spent less time on fluffy “love” stuff and more time telling us stories about saints like Fr. Pro.