Joe Biden is facing growing scrutiny over sexual assault allegations made by a former Senate staffer.

The big picture: Business Insider last week published two on-the record corroborations of parts of allegations by Tara Reade, who claims Biden sexually assaulted her in 1993. The former vice president then appeared on MSNBC's "Morning Joe" to publicly deny the allegations for the first time.

Timeline

April 3, 2019: Reade joined several women in accusing Biden of inappropriate touching as a senator in 1993. She told The Union, a local newspaper in California, that on numerous occasions Biden put his hands on her neck and shoulders in ways that made her uncomfortable.

Reade told The Union her responsibilities in Biden's office were reduced after she refused to serve drinks at an event. She said she left after nine months, feeling she was pushed out and that Biden's staff was protecting him.

She told The Union she didn't feel Biden's actions were sexualization, instead comparing her experience to being treated like a lamp: "It’s pretty. Set it over there," she said. "Then when it’s too bright, you throw it away."

Reade also tried unsuccessfully to get #MeToo-related Time's Up to help fund her case, per The Intercept.

March 25, 2020: Reade told journalist Katie Halper on a podcast that in 1993, Biden pinned her against a wall in a Senate building, reached under her clothes and penetrated her with his fingers while kissing her.

After pulling away, Reade recalled Biden telling her that he thought she liked him. Reade claims that Biden looked at her and said: "You're nothing to me" — words that she says affected her "almost more than the assault" because of how much respect she then had for him.

Reade said when Biden saw that she looked "shocked," he told her: "You're OK, you're fine."

Reade told Halper that she told family and a friend about the incident at the time.

April 9: Reade filed a police report claiming she was the victim of a sexual assault in 1993. She tweeted that she did so solely for "safety reasons," acknowledging that the statute of limitations had run out on her complaint.

April 12-13: The New York Times, Washington Post and AP all published investigations into Reade's allegations.

The Times interviewed Reade, lawyers she spoke to, nearly two dozen people who worked with Biden in the early 90s, and seven women who made inappropriate touching allegations against Biden. None corroborated the details of Reade's allegation, and the Times wrote that it "found no pattern of sexual misconduct" by Biden.

The Post interviewed Reade, more than a half-dozen former Biden staffers, and people Reade says she told about the assault soon after it happened. A friend who requested anonymity corroborated Reade’s account of their conversation. Reade's brother initially said she told him there was an incident where Biden was "inappropriate," but not the alleged assault. He later followed up and told the Post he recalled Reade telling him Biden had cornered her and reached under her clothes.

The AP interviewed Reade, five Biden staffers who worked with him at the time, and two friends Reade says she told about the incident before going public. One friend who requested anonymity said Reade told them about the assault at the time. The other friend said Reade told her about Biden's alleged harassment in 2007 or 2008 — but made no mention of the alleged assault.

April 24: The Intercept reported that Reade's mother called into CNN's "Larry King Live" on Aug. 11, 1993, and said her daughter had just left her job working for a "prominent senator" in Washington, where she "could not get through with her problems at all."

Reade's mother said "the only thing she could have done was go to the press, and she chose not to do it out of respect for him."

April 27: Two sources went on the record to Business Insider to corroborate certain details of Reade's allegation.

Lynda LaCasse, who was Reade's neighbor in the mid-1990s, said she told her in 1995 or 1996 that she had been assaulted by Biden: "I remember her saying, here was this person that she was working for and she idolized him," LaCasse said. "And he kind of put her up against a wall. And he put his hand up her skirt and he put his fingers inside her."

Lorraine Sanchez, who worked with Reade for a California state senator, said Reade told her in the mid-90s that "she had been sexually harassed by her former boss while she was in D.C., and as a result of her voicing her concerns to her supervisors, she was let go, fired." Sanchez said she does not remember if Reade gave details about the harassment she allegedly faced.

April 30: Reade told Fox News she filed a complaint to the Senate personnel office almost 30 years ago. Reade said the complaint would prove that she went to top Biden aides to discuss her problems with the then-senator, and that they have since lied about their recollections of those conversations.

May 1: Biden personally addressed the allegations for the first time on MSNBC's "Morning Joe," saying "They aren’t true. This never happened."

"I'm not going to question her motive. I'm not going to get into that at all. I don't know why she's saying this. I don't know why all of a sudden after 27 years this gets raised. I don't understand it," he added.

Biden then sent a letter to the Secretary of the Senate asking for a search of his records to locate Reade's alleged 1993 complaint about Biden.

May 2: Reade told the AP that she filed a "limited" report on Biden with a congressional personnel office that did not explicitly accuse him of sexual harassment or assault.

May 4: The Secretary of the Senate said it cannot comply with Biden's request to release documents pertaining to Reade's alleged 1993 complaint. The office said it "has no discretion to disclose" the information because of laws pertaining to confidentiality.

For the record: The Biden campaign has strongly denied all of Reade's allegations in statements provided to media organizations:

Kate Bedingfield, Biden's deputy campaign manager and communications director: "Vice President Biden has dedicated his public life to changing the culture and the laws around violence against women. He authored and fought for the passage and reauthorization of the landmark Violence Against Women Act. He firmly believes that women have a right to be heard - and heard respectfully. Such claims should also be diligently reviewed by an independent press. What is clear about this claim: it is untrue. This absolutely did not happen."

Marianne Baker, Biden's executive assistant from 1982–2000: "In all my years working for Senator Biden, I never once witnessed, or heard of, or received, any reports of inappropriate conduct. ... I have absolutely no knowledge or memory of Ms. Reade’s accounting of events, which would have left a searing impression on me as a woman professional, and as a manager."

May 7: Asked whether Biden should drop out in an excerpt of an interview with Megyn Kelly, Reade said: "I wish he would," adding it's "a little late" for an apology.

"You and I were there, Joe Biden. Please step forward and be held accountable. You should not be running on character for the president of the United States," Reade said.

May 22: Lawyer Douglas Wigdor, whose firm has represented plaintiffs in high-profile discrimination cases, announced that he was no longer representing Reade.