Dr. Conrad Murray is at fault for Michael Jackson's premature passing, she says.
"He was the one that was administering," she tells ABC's Robin Roberts in an exclusive interview airing Wednesday night. "I think he is responsible."
The doc is still under investigation for the death, and has admitted to giving the icon the anesthetic propofol.
Placing blame isn't the only thing Miss Jackson is spilling in the rare sit-down.
"I couldn't believe it," she says, recalling June 25 and the moment she found out her brother was deceased.
"I was at my house in New York," she remembers. "You know, another day. Another morning. And I get a call...[my assistant] said, 'Your brother's been taken to the hospital. It's on CNN right now.' I called everyone...I spoke to Mother. I spoke to Tito. I spoke to my nephew Austin. I spoke to my sister La Toya.
"I told them to call me when they got to the hospital. And I remember thinking, nobody's calling me back, so I tried calling again, and that's how I found out that he was no longer."
Not surprisingly, she was shocked.
"It didn't ring true to me," she recalls. "It felt like a dream. It's still so difficult for me to believe."
The public memorial service at the Staples Center in Los Angeles, she says, gave her a bit of closure.
Janet was understandably less open about people's accusations that Joe Jackson was an abusive father.
"You have to keep in mind that I'm the baby," the youngest of nine siblings circumvents. "I think it's old-school. And that may extrapolate into, ah, being a little abusive. Do you understand what I'm saying?"
Overall, 2009 has been a difficult and eventful 365 days for the pop queen.
"It's been a tough year," she says. "You have your days where it's just, really, it's hard to believe. And a day doesn't go by that I don't think about him."
Murray, for his part, hasn't had a great year, either.
Jackson's under-the-gun doc is due in court today for missing child-support payments.
His attorney Christopher Aaron says Murray was forced to shutter his medical practice and move as he received threats following Jackson's death. Because he has been unable to find work since, Dr. Murray will be asking the Las Vegas judge to allow him to make minimum payments for the time being.
Janet says the memorial at the Staples Center gave her closure. Relive the moving moments in our Mourning Michael Jackson gallery.