Cable news viewers following the Trayvon Martin coverage have been introduced this week to Joe Oliver, who has defended George Zimmerman on all four of the cable networks and ABC’s “Good Morning America” since Monday.

In an MSNBC interview with Lawrence O’Donnell yesterday, Oliver said he has been billed as a “close friend” of Zimmerman’s, a characterization he “wanted to clarify.” Oliver, a former local television anchor, described his relationship with Zimmerman as “more of an older uncle.”

“You’re a mystery man to me,” O’Donnell pressed him. “My role in this, I agree, just doesn’t make sense,” Oliver replied. Watch:

O’Donnell had also planned to interview Craig Sonner, Zimmerman’s attorney, on “The Last Word” Monday. But Sonner cancelled the interview at the last minute, and a furious O’Donnell instead interviewed an empty chair in his place. Video of the interview, as well as a “Daily Show” segment in response, is after the jump.