Lawmakers plan to hear testimony Tuesday from the woman who touched off a hiring scandal in the Murphy administration with her allegation that a former high-level staffer sexually assaulted her during last year's gubernatorial campaign.

The testimony from Katie Brennan, who is now chief of staff at the New Jersey Housing and Mortgage Finance Agency, is expected to be one of more closely watched events in Trenton since lawmakers held hearings on the Bridgegate scandal during Gov. Chris Christie's tenure.

Here is what you need to know:

What's happening

The Legislative Select Oversight Committee is scheduled to meet at 10:30 in the Statehouse for its first public meeting. Brennan is expected to testify about the sexual assault allegation against Al Alvarez, who led Latino and Muslim outreach during Murphy's gubernatorial campaign and was later hired as chief of staff at the Schools Development Authority.

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The investigation

Lawmakers formed the joint committee in October to investigate Murphy's hiring practices following the allegation.

Brennan, who volunteered on Murphy's campaign, said Alvarez forced himself on her following a campaign event in April 2017. She took her allegation to the authorities in Hudson County, who investigated it but did not file charges. Middlesex County is reviewing the file. Alvarez has denied the allegation and resigned in October.

The 15-member panel is investigating how Alvarez was hired, as well as the administration's screening of potential employees. Other Murphy hires have come under scrutiny because of their backgrounds — including Marcellus Jackson, a former Passaic councilman who served prison time for accepting bribes in office, and Derrick Green, who was involved in a Bermudan campaign finance scandal — but the panel has not announced details of future hearings.

“It is the mission of our committee to examine all aspects of the screening of prospective employees in state government and continued employment in the public sector of persons with questionable backgrounds, or pending allegations, including allegations or claims of sexual offenses,” Assemblywoman Eliana Pintor Marin, the panel's co-chairwoman, said in a statement last month. “After public hearings where we will take testimony, our joint committee will make recommendations to create improvements in screening and hiring practices. We intend to conduct our hearings professionally, fairly and as promptly as possible and deliver a report in an expeditious fashion.”

What's at stake

Although the committee's stated goal is to improve hiring practices, public hearings have the potential to create a distraction and test already-brittle relations between Murphy and fellow Democrats in the Legislature.

Murphy said Monday that lawmakers have "got to make sure they don't get political" in their investigation, and his aides reportedly pressed lawmakers to restrict the inquiry or skip it all together. Sen. Loretta Weinberg, co-chair of the committee, told Politico New Jersey " I haven’t felt any pressure directly from his aides or him — nothing that I would respond to.”

As the investigation begins, Murphy and lawmakers remain at odds over proposals to legalize marijuana and raise the minimum wage to $15 an hour, two of Murphy's biggest campaign promises.

Who's on the committee?

Most of the members are women. Weinberg and Assemblywoman Eliana Pintor Marin chair the committee.

The other members are: Assemblywoman Nancy Munoz, R-Union, who will serve as vice chairwoman; Assemblywoman Angela McKnight, D-Hudson; Assemblywoman Pamela Lampitt, D-Camden; Assemblywoman Verlina Reynolds-Jackson, D-Mercer; Assemblyman Gordon Johnson, D-Bergen; Assemblywoman Nancy Pinkin, D-Middlesex; Assemblywoman BettyLou DeCroce R-Morris; Assemblywoman Holly Schepisi, R-Bergen; Sen. Sandra Cunningham, D-Hudson; Sen. Teresa Ruiz, D-Essex; Sen. Fred Madden, D-Gloucester; Sen. Kristin Corrado, R-Passaic; and Sen. Steve Oroho, R-Sussex.

This report is brought to you by USA TODAY NETWORK New Jersey, which is made up of news organizations APP.com, CourierPostOnline.com, TheDailyJournal.com, DailyRecord.com, MyCentralJersey.com and NorthJersey.com.