Utah Republican Sen. Mike Lee on Tuesday deleted a series of inflammatory social media posts from over the weekend in which he reacted to the shooting deaths of Minnesota state representatives, prompting a confrontation with the state’s Democratic US senator.

In an interview with MSNBC’s Joe Scarborough Klobuchar says Lee’s tweets make light of the fatal shooting.. including one calling the situation a “Nightmare on Waltz Street” she says she plans to confront him directly about the issue.