He was arrested in the fall of 1847 for the murder of Edward Matthews in Waterville. A newspaper account noted that "the unfortunate man was poisoned by prussic acid, which was administered to him in a glass of brandy." Matthews' body was discovered on a pile of wood in a cellar; his watch was found in Dr. Coolidge's sleigh, and his money was found secreted in a shed. A student of Coolidge's named Flint came forward, saying that he had aided in disposing of the body. The doctor had told Flint that Matthews died of natural causes in his office, and that he wanted to be spared the embarrassment of having the body found there.
Coolidge was convicted the following March of murder, and was sentenced to a year in the State Prison at Thomaston, followed by his execution.
Here's where the story gets interesting.
On the morning of May 18, 1849, Coolidge was reportedly found dead in this cell — an apparent suicide. A short time prior to his death, evidence was found of his plotting the murder of Dr. Flint — his former student and witness against him. He had forged a confession to Matthews' murder in Flint's handwriting, and had enlisted a fellow prisoner to kill Flint and stage a suicide. When the warden discovered this evidence, he confined Coolidge to his cell, where he was found dead two days later.
But, was he really dead?
No jury of inquest was called to investigate the alleged suicide, and doubts immediately arose whether Coolidge was in fact deceased. A Dr. Mann pressed the inquiry, and collected affidavits, including one from Coolidge's father, who stated his belief that a stranger had been buried in his son's place.
Dr. Coolidge's body was disinterred from its resting place in Canton twice to determine the corpse's identity. On both occasions, relatives and acquaintances declared that it was not Valorus P. Coolidge. Then, in November of 1849, a letter was published in New England newspapers, dated "Short Bar, 30 miles from Colona, California, Sept. 3d." and addressed to a man in Boston:
Yesterday morning there came up here three strangers from Sacramento city, one of whom I recognized as the notorious Dr. Valorus P. Coolidge, formerly of Waterville, Me., the alleged murderer of Ed. Matthews. Could I be mistaken? How came he here? Has he escaped hanging? I knew Coolidge well, at Waterville, and if this is not him, then I never saw the man. His beard was very thin and scattered over his thin, narrow face, but it had grown out two or three inches in length. He passed here by the name of Wilkes or Wilkins. His eye I could not mistake. He appeared well, but in no other way altered, save that he was meanly dressed, and looked a little harder than usual. I told my belief to W., and the next morning Coolidge was gone. Where he has wandered I cannot guess, but I feel sure it was him. If you ever write, tell me what this can mean. Or am I deceived?The grave of Valorus P. Coolidge's body-double can be seen in a recently re-discovered cemetery in Canton, near the town-lines of Jay and Livermore. Who inhabits the grave, and what became of the doctor, are unknown.