Very interesting detial in NSO Group's training materials for customers:
"Pegasus training material describes situations where it may not be possible to attack a target directly, for example if they do not use a smartphone or are highly security conscious in how they use their device. In those circumstances, NSO Group suggests expanding to 'close-circle infection,' targeting others connected to the target, potentially including colleagues, friends or family members of the primary target in order to gather information about them indirectly."
There have been several documented cases of this happening, including to people close to murdered Saudi journalist Jamal Khashoggi.