On December 4, 2017, Pamela Lopez, a Sacramento lobbyist, alleged that Dababneh sexually assaulted her. According to Lopez, in 2016 Dababneh pushed her into a Las Vegas hotel bathroom, masturbated in front of her and urged her to touch him. "I felt the weight of a body push me into the restroom." Dababneh has strongly denied the allegation, and his attorney Patricia L. Glaser, who also represents embattled film producer Harvey Weinstein, threatened to sue Lopez for defamation. "I affirmatively deny that this event ever happened," said Dababneh. "I am saddened by this lobbyist's effort... for her own self-promotion." Jessica Y. Barker, who was Dababneh's subordinate when they both worked in US Congresman Brad Sherman's District Office, also came forward and accused Dababneh of sexual harassment. According to Barker, Dababneh regularly spoke about his sexual exploits and made degrading comments about women. She said his behavior was the main factor in her decision to leave her job as a field representative for the congressman after 18 months. She said over the course of her tenure there that Dababneh frequently made inappropriate comments at work, including talking about his sexual habits and the attire of female staffers. Two friends confirmed to The Los Angeles Times that Barker regularly told them about Dababneh's behavior and that she said it made her feel uncomfortable. According to Barker, "Pamela and I aren't the only women that Matt has harassed. There are others and I have spoken to them." On December 5, Assembly Speaker Anthony Rendon announced that the Assembly Rules Committee would hire an outside law firm to investigate the incident described by Pamela Lopez, and Dababneh would temporarily step down as chair of the Assembly Banking and Finance Committee. On December 8, Dababneh announced that he would resign at the end of the month. He said he didn't feel pressure to resign because of the allegations, for which he maintains his innocence, but he said he simply no longer felt passionate about lawmaking and was ready for a change. After hearing of Dababneh's resignation, Lopez said this was only the beginning if he wanted to truly atone for his actions. She called on him to donate his 2018 campaign money to a rape crisis or trauma center. Lopez also announced that day she'd heard from several other women with allegations against Dababneh that ranged from sexual harassment to assault. According to the Los Angeles Times, "Preliminary findings by an independent investigator hired by the Assembly Rules Committee substantiated Lopez’s allegation in June. The conclusion was based on interviews with Lopez and more than 50 witnesses. Dababneh also participated in the investigation."
Dababneh took office in January 2014, after winning the November 2013 election to complete the remaining 2014 term vacated by the 2013 resignation of Bob Blumenfield to represent Los Angeles City Council District 3. Dababneh won the seat in closely contested run-off election after finishing 329 votes ahead of his opponent. He won a full term in 2014, and secured a spot in the general election of 2016 finishing as the top vote getter in June primary with 49.24% of the vote. This came after Dababneh received more than $350,000 in outside money in support of his re-election bid. Prior to the June 2016 primary he faced criticism from local Democratic activists for positions he had taken while in office. In March 2017, Dababneh coauthored the controversial California Senate Bill 649 which would remove a city's ability to control where the technology is placed and transfer that power to the state and is considered "an unconstitutional bill that forcibly exposes neighborhoods to constant, hazardous 4G/5G microwave radiation."
