How Can You Tell Who is Pinging?

Apologies if this is not the proper place to ask this.

I recently was playing a round of coop vs. ai to get use to the new rotation of characters. During one of the matches, one of the other players began to spam ping. Everyone accused each other of doing it. I'm fairly certain of which person did it, but I still can't tell who it was for sure.

I know that when someone targets a person or puts down a special ping ("On the way" "Caution" etc) it makes a chat message, but these were just generic pings with no name or message. Is there any way to know who is doing it? We had a brand new player in the group and I hate that this was their first view of LoL.