The Eleventh Hour Intervention
If you want the blow-by-blow rundown of the police investigation and trial of Henri Pranzini, Catholic World Report has an excellent rundown of the case.
The story in the words of St. Therese, from The Story of a Soul:
In order still further to enkindle my ardor, Our Divine Master soon proved to me how pleasing to him was my desire. Just then I heard much talk of a notorious criminal, Pranzini, who was sentenced to death for several shocking murders, and, as he was quite impenitent, everyone feared he would be eternally lost. How I longed to avert this irreparable calamity! In order to do so I employed all the spiritual means I could think of, and, knowing that my own efforts were unavailing, I offered for his pardon the infinite merits of Our Savior and the treasures of Holy Church.
Need I say that in the depths of my heart I felt certain my request would be granted? But, that I might gain courage to persevere in the quest for souls, I said in all simplicity: "My God, I am quite sure that Thou wilt pardon this unhappy Pranzini. I should still think so if he did not confess his sins or give any sign of sorrow, because I have such confidence in Thy unbounded Mercy; but this is my first sinner, and therefore I beg for just one sign of repentance to reassure me." My prayer was granted to the letter. My Father never allowed us to read the papers, but I did not think there was any disobedience in looking at the part about Pranzini. The day after his execution I hastily opened the paper, La Croix, and what did I see? Tears betrayed my emotion; I was obliged to run out of the room. Pranzini had mounted the scaffold without confessing or receiving absolution, and the executioners were already dragging him towards the fatal block, when all at once, apparently in answer to a sudden inspiration, he turned round, seized the crucifix which the Priest was offering to him, and kissed Our Lord's Sacred Wounds three times. . . . I had obtained the sign I asked for, and to me it was especially sweet. Was it not when I saw the Precious Blood flowing from the Wounds of Jesus that the thirst for souls first took possession of me? I wished to give them to drink of the Blood of the Immaculate Lamb that It might wash away their stains, and the lips of "my first born" had been pressed to these Divine Wounds. What a wonderful answer!
Henri Pranzini’s police mugshot
St. Therese of Lisieux at age 13. She was 14 at the time of this story.
St. Therese of Lisieux at age 15. This picture was taken the day she went to visit the bishop to ask permission to enter Carmel. She put her hair up in an attempt to look older.