Ellery Queen Mystery Magazine In The 1980S

[utepoot]

I read a story back in the early eighties, but I can't remember who wrote it, or the title. All I remember is the main character was a policeman, and the "villain" in the story was using a sort of mirroring technique to annoy other people. By mirroring I mean projecting back the same voice inflections, tone and speech pattern as the person who spoke to him, but he changed the speed of the speech to make it slightly slower, and that somehow made the other person quite uneasy. I can't remember the actual crime(s) that were committed, or anything else, really. I think the "perp" may have been a teenager or youngish adult. I think I would have read the story between 1980 and 1986. Any help would be greatly appreciated, this is really annoying me now, and can't find anything online that helps, other than buy all the back issues within that time period, which I can't afford! I have contacted the actual magazine themselves, but no one could help me.