There’s a difference between speculation and making inferences. Jurors are not allowed to speculate, but they are allowed to infer. They are actually encouraged to infer and use their reasoning skills. Using your example, there was enough evidence for the jurors to infer that Erin visited the death cap locations because she saw the posts.
Here’s a ChatGPT breakdown:
The difference between speculating and inferring comes down to evidence and certainty:

Inferring
- Based on evidence.
- You draw a logical conclusion from known facts or observations.
- It’s grounded in reasoning.
Example:
You see someone running with an umbrella, and the ground is wet.
→ You infer that it’s raining or just rained.

Speculating
- Based more on guesswork.
- You form an idea or theory without strong evidence.
- It often involves imagination or possibility.
Example:
You see someone running with an umbrella, but the sky is clear and the ground is dry.
→ You speculate that they might be practicing for a play or worried about sun exposure.