I have previously posted about “context testimony” usually from law enforcement officers to set the stage for why an investigation began. While not exactly addressing this issue, NMCCA has come close and has a useful discussion of how similar context evidence is not admissible.
In United States v. Combest (an unpublished op.) the court sets the facts.
Soon after arriving home [from apparently being assaulted], DW told her sister, AH, that she had been sexually assaulted by the appellant. AH then called the police. It is DW’s statement to AH that gives rise to the appellant’s assignment of error.