I have a question about Roland's reaction ability, which reads as follows: "After you defeat an enemy: Discover 1 clue at your location. (Limit once per round.)"

What happens if Guard Dog deals lethal damage to an enemy? Does Roland still get a clue? Assuming, of course, that there is a clue to be discovered on current location.

Similarly, if Roland uses Beat Cop's free-trigger ability to deal 1 damage to an enemy, and that damage kills the enemy, does Roland earn a clue?

I would think Roland would earn the clue in either situation since Guard Dog/Beat Cop are under Roland's control, and thus used as tools to defeat the enemy. Can someone please confirm?

Its still Rolands Deck so Its a win and a clue for Roland, well that is my understanding of the rules

Yes, Roland gets clues in all the above scenarios. The investigator who dealt fatal damage defeated the monster, and you deal all damage from sources you control.

Thanks guys! Totally makes sense.