Legal Question in Criminal Law in Michigan

Usually when the opposing party fails to object to its introduction.

YOU think "it has nothing to do with the case on hand", but one or more of the lawyers do (apparently).

"Past events" can be relevant to current event/case issues. There are too many examples and reasons to even begin to list here ... especially when you gave us no factual context (what was the current case about, what were the charges, what was the 'past event' evidence, etc.).

Judges rule on whether something is relevant when a party makes a timely objection that the evidence is NOT relevant. As Mr. Morrison noted, if one attorney is asleep at the switch, things can come in that might not otherwise come into the trial record.

On the other hand, both attorney may have known that this historical information was relevant and the judge would have denied the objection, which may be why there was no objection.