In a criminal case, you generally have to prove things “beyond a reasonable doubt,” which is an extremely high standard, sometimes described as 99% positive. In contrast, the general standard in civil cases is “by a preponderance of the evidence,” which is just a fancy way of saying more likely than not or anything above 50%.
Thus, a civil plaintiff—the one asserting the claim—only needs to convince the jury or judge that it is ever so slightly more likely that the plaintiff’s story is the right one. These are only the general standards—certain issues in civil or criminal cases may be governed by other standards, such as the “clear and convincing evidence” standard, which requires a demonstration that the thing in question is highly probable (often approximated at 85–90%).
If you have questions, feel free to contact my office for more information.