Final answer:
Jean Gianini was the man who shot Meredith and confessed to the crime. He murdered his former teacher and was later deemed legally insane during the commission of the crime.
Step-by-step explanation:
The man who shot Meredith and confessed was Jean Gianini, a sixteen-year-old student from Poland, New York.
He murdered his former teacher, Lydia Beecher, in 1914 and provided evidence that tied him to the crime.
Gianini confessed to the murder and his defense lawyers argued that he was legally insane. Psychologist Dr. Henry Herbert Goddard testified as an expert witness during the trial.