Complex sentence: Today it is colloquially referred to as a rape test kit or a rape kit, which is used interchangeably to refer to the specific evidence that is obtained through the use of the rape kit.
Split into simpler sentences: Today it is colloquially referred to as a rape kit or a rape test kit. In the context of a specific case, the term "rape kit" is also used to refer to the collected evidence that was obtained through the use of a rape kit.