04/07/2015 04:40 EDT | Updated 06/07/2015 01:12 EDT

A look at some of the less familiar faces to appear in the Mike Duffy trial

OTTAWA - Dozens of people are expected to make an appearance in an Ottawa courtroom over the next several weeks as suspended senator Mike Duffy stands trial on charges of fraud, breach of trust, and bribery.Here's a guide to some of the people who are expected to be on hand.

___The Men in RobesOntario Justice Charles Vaillancourt: The Toronto-based judge presiding over the case.Mark Holmes and Jason Neubauer: Crown attorneys from Ottawa with signficant criminal convictions under their belts.Donald Bayne: A veteran Ottawa-based criminal defence lawyer with experience in government inquiries and high-profile cases involving murder, war crimes, and conspiracy.___Former Prime Minister's Office StaffNigel Wright: Ex-chief of staff to Stephen Harper. Secretly repaid $90,000 of Duffy's contested Senate living expenses in 2013. Back working now for private equity firm Onex, in London.Benjamin Perrin: Former legal adviser in the PMO. Perrin has said he did not participate in Wright's decision to cut Duffy a cheque. RCMP documents show Perrin negotiated directly with Duffy's lawyer to set the terms of the repayment.David van Hemmen: Van Hemmen was Wright's former executive assistant, and knew about the $90,000 cheque. Currently the director of budget planning for Finance Minister Joe Oliver.Chris Woodcock: Former PMO director of issues management, who worked with others on reshaping a Senate committee report on Duffy and developing media lines for the senator. Now an executive at the Canada Mortgage and Housing Corp.___The SenateConservative Sen. Marjory LeBreton: Former Government Leader in the Senate. LeBreton complied with PMO desire to try and close the book on the Duffy expense issue after repayment. Scolded behind the scenes for not controlling situation better.Conservative Sen. David Tkachuk: Part of a three-member sub-committee which prepared a whitewashed report on Duffy's living expenses. Conservative Sen. Carolyn Stewart Olsen: A member of the same Senate committee. Relayed back to committee changes the PMO wanted to the Duffy report and voted for the edits.Chris Montgomery: Former head of issues management inside LeBreton's office. Pushed back at PMO's meddling in the Senate committee report on Duffy. Now works for Canadian Association of Petroleum Producers.Gary O'Brien: Recently retired clerk of the Senate.Nicole Proulx: Senate's chief corporate services director, formerly finance director. ___Duffy ContractorsGerald Donohue: A friend of Duffy's from TV days. Duffy awarded him money for contracts for consulting and writing services. Police allege no real work was done. Ezra Levant: Television commentator and columnist. Received contract money for speeches written for Duffy.Mike Croskery: A personal trainer who police allege received more than $5,000 in Senate funds via Duffy.