Final answer:
A presumptive ID is based more on context and circumstantial evidence, while a positive ID relies on more definitive evidence like DNA matching. A tattoo match alone would not be sufficient for a presumptive ID.
Step-by-step explanation:
A presumptive ID differs from a positive ID in that it is based more on context rather than something like DNA evidence. A presumptive ID is a preliminary or tentative identification that is made based on available evidence, but it may not be conclusive. On the other hand, a positive ID is based on more definitive evidence and provides a higher level of certainty.
For example, let's say a suspect is identified based on a witness's description and some circumstantial evidence. This would be considered a presumptive ID because it is not based on irrefutable evidence like DNA matching or fingerprint analysis. However, if DNA evidence is later found and it matches the suspect, then it becomes a positive ID.
So, option a is correct because a presumptive ID relies more on context and circumstantial evidence than concrete evidence like DNA matching. Option c is incorrect because a tattoo match alone would not be sufficient for a presumptive ID; it would still require additional supporting evidence.