Defence lawyer Donald Bayne introduced into evidence Thursday two oversized photographs featuring Duffy and Harper at public events. They promptly wound up displayed on the wall next to the accused, for all present to see.
"To Duff: A great journalist and a great senator," read the inscription on one of the photographs of the pair, taken five months after Duffy was appointed to the Senate in December 2008.
"Thanks for being one of my best, hardest-working appointments ever! Stephen Harper."
The other photo depicts Harper and Duffy at a 2010 event on Parliament Hill, the two men sitting face to face on a public stage.
What do the photographs have to do with Duffy's 31 charges of fraud, breach of trust and bribery? Plenty, as Bayne's argument goes.
Eighteen of the charges deal with travel claims in which Duffy said he was on Senate business. The Crown has alleged Duffy was attending to personal matters and going to partisan events — travel the taxpayer shouldn't have paid for.
Bayne is making the case that any kind of political activity or event passes muster as far as the rules go — and besides, Harper made it clear he wanted the former broadcaster on the road, supporting the Conservatives.
In a second day of cross-examining former Senate law clerk Mark Audcent, Bayne emphasized the broad definition of what constitutes Senate business.
"Sen. Duffy played a very highly active partisan role for the prime minister, after his appointment, very soon after his appointment, and started to appear with him personally," he said.
Bayne took Audcent through the Senate administrative rules that he helped draft in 2004, and the definition of a senator's parliamentary functions. One section of the rules calls partisan activities an "inherent and essential" part of a senator's life.
"Partisan activities are not a sideshow in the Senate, they aren't peripheral, they aren't whatever the public thinks," said Bayne.
"In reality, partisan activities are inherent and essential as part of the parliamentary function of a senator."
"I agree," said Audcent.
Audcent also agreed with Bayne's analysis that there are really no limitations to what constitutes legitimate activities for a senator — with the exception of campaigning for an MP during an election, or private business.
Bayne: "There's an immense range of activity that fall as senatorial activities."
Audcent: "Completely, yes."
In one instance, Duffy said he was scheduled to attend an event with then-cabinet minister Gary Lunn on Vancouver Island. That event was cancelled, but Duffy spent time visiting with family in the area.
The early part of the day's testimony revolved around Duffy's residency issues. The minutiae might have caused a few yawns, but one courtroom spectator was listening very closely.
Fellow suspended senator Patrick Brazeau sat in the back of the room, listening carefully and taking copious notes.
Brazeau and Duffy, once colleagues in the Conservative caucus, both face charges related to living and travel expenses they filed for having a primary residence outside of the Ottawa area.
"I'm here to support my independent senator," Brazeau said as he arrived at the Ottawa courthouse.
Duffy said his primary residence was a home in Prince Edward Island, despite the fact he lives most of the time in suburban Ottawa. He made claims of about $82,000.
Brazeau said he lived in Maniwaki, Que., but police allege that he actually lived in Gatineau, across the river from Ottawa. He has already had his salary garnisheed to pay back the Senate for $50,000 it said he owed the public purse.
Brazeau is likely not the only senator who will be watching the Duffy trial closely. Sen. Pamela Wallin faces similar charges relating to her expenses, and the auditor general is currently reviewing the books of other senators.
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