Rep. Maxine Waters on Friday is expected to be cleared of charges in a Congressional ethics investigation that has spanned three years.

The verdict would clear the way for the California Democrat to pursue the title of top Democrat on the Financial Services Committee as ranking member Barney Frank (D-Mass.) prepares to retire at the end of this Congress.

According to a source familiar with the situation, however, Waters’ staff would not be entirely off the hook: Her chief of staff and grandson, Mikael Moore, is likely to be held accountable for breaching House codes of conduct.

The source told Roll Call that when the House Ethics Committee meets in a rare public hearing at 9:15 a.m. Friday, Moore will likely be held accountable for seeking to leverage Waters’ influence as a member of the Financial Services panel to aid OneUnited Bank, in which Waters’ husband has a stake.

Waters has been facing similar conflict of interest charges since 2009, when the independent Office of Congressional Ethics first took up the case.

Just days before a rare public ethics trial was slated to begin in November 2010, the committee announced it would be sending the case back to the investigative subcommittee “due to materials discovered that may have had an effect on the investigative subcommittee’s transmittal.”

Shortly thereafter, it was revealed that two staffers were placed on administrative leave and that the former staff director had resigned. Later, internal committee documents published by Politico showed the committee’s former staff director thought the staffers’ improper behavior had likely compromised the investigation.

The leaked communications raised questions about whether then-Ethics Chairwoman Zoe Lofgren (D-Calif.) and ranking member Jo Bonner (R-Ala.), who now chairs the committee, had allowed partisanship to affect the committee’s investigation.

Waters argued that her due process rights had been violated and that the committee should abandon the charges. In July 2011, the committee hired outside counsel Billy Martin to determine whether committee members and staffers had acted in a way that improperly impacted Waters’ case. Martin was asked to determine whether the case should be dropped, restarted or proceed.

Martin’s report, released in June of this year, revealed no indication that Waters had been deprived due process in the committee’s handling of her case, clearing the way for Friday’s conclusion.