Perhaps Uhlman et al (2015) or Landy & Uhlmann (2018)?
From the latter:
Evidence for this assertion comes from studies involving two jilted lovers (Tannenbaum et al., 2011, Studies 1a and 1b). Participants were presented with information about two men who had learned that their girlfriends were cheating on them. Both men flew into a rage, and one beat up his unfaithful girlfriend, while the other beat up her cat. Participants judged the former action as more immoral, but judged the catbeater as having worse character (specifically, as being more lacking in empathy) than the girlfriend-beater. This is an example of an act-person dissociation.
Perhaps Uhlman et al (2015) or Landy & Uhlmann (2018)?
From the latter:
I think it was the first one. Well done for finding it!