Very interesting. This was the son of the same Pope that had the "Dance of the Chestnuts" a night full of orgies and rewards from the Pope for those who were the most promiscuous.
If each murder was a life sentence, he must have killed only 5-10 people.
Most of these stories are from the time after Alexander VI's death, and were passed around by his enemies. If you step back and actually consider the nonesense of some of what is written about him (how is it physically possible for his body to "to swell so much that it became as wide as it was long", according to Burchard, who is so trusted by the slanderers of this Pope?). When one wishes to believe anything it is quite easy to manufacture all manner of spurious tales.
I've read that, when Alexander VI died, the rector of St. Peter's refused to let Masses be sung there for the repose of his soul. "It is blasphemous to pray for the souls of the damned," he said.
As far as his personal morality was concerned, Alexander VI was the worst Pope in history.