Just Caught an Episode For the First Time: Valerie Gardner
The episode that I watched was about "Valerie Gardner". I decided to do a bit of googling and they really do take so many liberties with these stories.
Not sure if this has been mentioned before (doesn't seem like it) but it took place in France and the death did not occur on the tennis court. The murderer was a former French army pilot and it was his 15 year old son that was playing in the matches was a (not a daughter) though he did have a daughter as well. The competitor who died was a 25 year old male. He had pulled out of the tournament because he felt awful from the Temesta. They believe he fell asleep at the wheel and that's how he died.
The crime carried up to 20 years in prison and he got 8. The son never became a champion, but the daughter apparently has found some success.
All in all he drugged 27 people.