Which preposition to use with autopsy

of Occurrences 2%

At the autopsy of her body Maestro Pasquali of Florence declared that death was caused by putrid fever!

ON Occurrences 1%

[From the Medical Record, New York, 1881, vol. 20, p. 364.] OFFICIAL BULLETIN OF THE AUTOPSY ON THE BODY OF PRESIDENT GARFIELD.

to Occurrences 1%

Chatterton makes us lenient to a life of fraud by the dogged and cynical uncomplainingness of the despair that drove him to cut it short; but Haydon continues his self-autopsy to the last moment, and in pulling the trigger seems to be only firing the train for an explosion that shall give him a week longer of posthumous notoriety.

Which preposition to use with  autopsy