Appearing on CNN's State of the Union, Collins told host Dana Bash she believes Ford -- who accused Kavanaugh of sexually assaulting her at a party while they were both in high school -- was assaulted, but didn't believe Kavanaugh was responsible.
"I do not believe that Brett Kavanaugh was her assailant," said Collins, R-Maine. "I do believe that she was assaulted. I don't know by whom. I'm not certain when."
Collins added Kavnaugh and Ford appeared entirely certain of their telling of the events during the testimony so she turned to the FBI's supplemental background investigation of Kavanaugh for corroborating evidence.
"I found Dr. Ford's testimony to be heart-wrenching, painful, compelling, and I believe that she believes what she testified to," she said. "But we also had a case where Judge Kavanaugh came forward and said, 'I'm 100 percent certain that this did not happen,' so here you have two people who are each 100 percent certain of what they're saying under pain of perjury. So then I had to look at the other evidence, and was there corroborating evidence, and that's why I pushed hard for the FBI to do a supplemental background investigation."
Addressing Kavanaugh's demeanor during the hearing, Collins said she believed Kavanaugh "stepped over the line" by referring to revenge for an orchestrated plot by the Clintons in his opening statement and his responses to certain senators, including Amy Klobuchar.
Collins said she sought however to empathize with Kavanaugh considering the allegations brought against him by Kavanaugh and two other women.
"I put myself in his shoes," she said. "He is coming forth and answering an allegation that includes that he was involved in gang-raping and doping girls. I mean, that is so devastating. And I think he reacted with anger and anguish as a father of two young girls, a 10-year-old and a 13-year-old."
"I thought that Susan was incredible yesterday. You could see how hard she worked, how hard she was working. She didn't stop," Trump said. "And I know it for a fact because I spoke with her, she didn't stop. She gave an impassioned, beautiful speech yesterday. And that was from the heart, that was from the heart."
Sen. Mazie Hirono, D-Hawaii, also appearing on the CNN news show, described Collins' attitude as "insulting" to Ford and other sex assault victims.
"She said that Dr. Ford thinks that she was assaulted, which is even more insulting than saying that she gave a very credible account ..." Hirono said. "What is that? Is [Ford] mistaken?"
Kavanaugh is expected to appear on the Supreme Court bench for the first time Tuesday as the court will hear arguments in three criminal cases regarding the so-called three-strikes law, which applies a 15-year mandatory minimum to federal offenders with three previous convictions, Politico reported.
He could also provide a vote on a request by the Trump administration to block depositions of Commerce Secretary Wilbur Ross and Justice Department civil rights chief John Gore in lawsuits challenging Ross' decision to put a question about citizenship on the 2020 U.S. Census.