Double jeopardy is a legal principle that prevents a person from being tried twice for the same offense after either an acquittal or a conviction. In your examples, the instances of double jeopardy would be:
- Being sued for causing Jack Smith’s death after being found not guilty of Jack Smith’s death.
- Being tried for the murder of Jack Smith after being found not guilty for murdering Jack Smith.
Both of these examples involve addressing the same charge against the same person after they have already been acquitted of that charge.
The third example, "being tried for the murder of Jack Smith after being found not guilty for murdering Joe Smith," does not constitute double jeopardy, as it involves a different victim.
The last example, "being tried for the murder of Jack Smith after the first murder trial ended in a mistrial," also does not constitute double jeopardy, as a mistrial does not constitute a verdict of not guilty.
So, the correct answers related to double jeopardy are the first two examples.