The top US diplomat in Ukraine, Bill Taylor, testified behind closed doors Tuesday as part of the ongoing impeachment inquiry led by House Democrats. In his opening statement, Taylor gave an account of his concern, beginning in August of this year, that the US relationship with Ukraine "was being fundamentally undermined by an irregular, informal channel of U.S. policy-making" led by President Donald Trump's personal attorney, Rudy Giuliani.

Over the last three decades, Aaron and Barbara Levine have amassed an impressive melange of conceptual and minimalist art. But, they jokingly say, they loathe calling it a "collection."

Former Homeland Security Secretary Kirstjen Nielsen on Tuesday said she left office because "saying no" and refusing to do things that others in the administration wanted was "not going to be enough."

The remains of a 3-year-old child found in a Birmingham, Alabama, landfill are believed to belong to Kamille "Cupcake" McKinney, a child who had been missing for a little more than a week, police said.

Across the globe, from Lebanon to Iraq, Chile to Haiti and Hong Kong, people are taking to the streets in thousands, telling their leaders: enough is enough.

"Quid pro quo," the term you can't escape (let alone pronounce). CNN's Jeanne Moos reports on mangling "quid pro quo."

Longtime Oakland Raiders defensive back and Hall of Famer Willie Brown has died at 78, according to the Pro Football Hall of Fame.

Freshman Democratic Rep. Katie Hill of California on Tuesday denied an allegation that she was in a relationship with a member of her congressional office staff and said that she has notified Capitol Hill police that intimate photos of her were posted online without her consent.

When the House of Representatives launched its impeachment inquiry into President Donald Trump over the Ukraine scandal, the White House decried it as "invalid" and "baseless," and ordered some subpoenaed officials not to testify to Congress. This obstructionist strategy worked once before, as the White House effectively stonewalled the House Judiciary Committee's investigation of Robert Mueller's findings on Russian election interference by instructing executive branch employees not to comply with subpoenas.

CNN's Anderson Cooper speaks with singer Mike Posner, who just finished his six-month trek across the United States. Watch "Full Circle" every weeknight at 5pm E.T.

Authorities have detained one person in connection with a shooting Tuesday near Ridgway High School in Santa Rosa, California, police said.

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