A second woman has come forward to accuse Sen.
Menz said she met Franken at the Minnesota State Fair seven years ago with her husband and father and asked for a photo with the lawmaker.
Menz's allegation comes days after a Los Angeles broadcaster, Leeann Tweeden, accused Franken of forcibly kissing her during a 2006 USO tour.
Franken wrote in his apology to Tweeden, "I am asking that an ethics investigation be undertaken, and I will gladly cooperate". Menz said she had a brief and cordial exchange with the senator. Neither, they said, is registered with a political party. According to Lindsay and her husband Jeremy, Franken pulled Lindsay close for the picture.
Lindsay Menz explained that Al Franken, elected in 2008 in the Senate, he had put a hand to the butt while he posed with it for a photo taken by her husband at a fair in Minnesota.
"It was wrapped tightly around my butt cheek", Menz said.
Husband Jerry Menz told CNN that Franken "reached around her and kind of pulled her into him".
Noting that the touch lasted a few seconds, Menz said, "I was like, oh my God, what's happening". It was over pretty quick. You just feel gross. "Like ew, I want to wash that off of me", Menz said.
Menz' Twitter account says she lived in Minneapolis.
In the photo of Menz and Franken, the side of the senator's face is pressed up against Menz's but the lower halves of their bodies are not shown.
"I had a lot of ideas for legislation, and I was hoping that the personal connection would help me get some time with his office, and it did", Honold told CNN of approaching Franken about sponsorship. He has since apologized to her but added that he remembers their encounter differently. "The reason I want to say something is if someone sees that I said something, maybe it would give them the courage to say something too". Franken's office had been working with her on crafting the piece of legislation for about a year, Honold said.