'Start Here': Giuliani in Ukraine amid impeachment inquiry and Uber reveals thousands of sexual assault reports in safety study

Here's what you need to know to start your day.

It's Friday, Dec. 6, 2019. Let's start here.

1. Where's Rudy?

The president's personal attorney is working with One America News Network (OAN) to discredit what the far-right network calls "the impeachment hoax" and offer proof of Ukrainian corruption and 2016 election meddling, according to an OAN spokesperson.

Despite heightened scrutiny in the impeachment inquiry and a campaign finance case involving two of his associates in the Southern District of New York, Giuliani is "not letting up on his investigation," ABC News Senior Editorial Producer John Santucci tells "Start Here."

"We know that from hearings over the last couple days that his associates have information that they believe is important to the impeachment inquiry," he says. "We also know that Giuliani's business, Giuliani Associates, received a subpoena recently asking for documents and records related to Rudy's work abroad. And ironically, where's Rudy right now? Abroad."

In a highly-anticipated safety report, Uber has revealed that nearly 6,000 sexual assaults involving drivers and passengers were reported to the ride-share company in 2017 and 2018.

ABC News' Taylor Dunn breaks down Uber's findings on the podcast and talks about next steps for the company.

Uber noted that "riders account for nearly half (45%) of the accused parties across the 5 most serious sexual assault categories" in the study, but added that "any safety issue is exceptionally rare" and "by bringing hard data to bear, we can make every trip safer for drivers and riders alike."

3. Border custody death

There's growing backlash over the death of Carlos Vasquez, a 16-year-old migrant, in a Border Patrol cell after video surfaced showing his final hours in May as he suffered from the flu.

Current and former Border Patrol officials told ABC News Chief National Correspondent Matt Gutman that the agency was overwhelmed with migrants at the time and they conducted welfare checks, but the video obtained by ProPublica appears to indicate otherwise.

"Had he been taken to the hospital, he would have survived," Gutman says. "Instead, he was taken to this cell. It is basically like a drunk tank, for all intents and purposes, with a concrete bed, and that's where he spent his final minutes."

"Start Here," ABC News' flagship podcast, offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, iHeartRadio, Spotify, Stitcher, TuneIn or the ABC News app. Follow @StartHereABC on Twitter, Facebook and Instagram for exclusive content and show updates.

Elsewhere:

'Lots of co-hosts from the entertainment community': Sen. Elizabeth Warren, D-Mass., is set to host her first campaign fundraiser in the Los Angeles area Saturday.

'The Motion for Withdrawal is hereby granted': Without warning or explanation, the attorney prosecuting the death-penalty case of the woman accused of killing former Arkansas state Sen. Linda Collins-Smith dropped out of the proceedings altogether this week.

'Highly insensitive and completely inappropriate': Several West Virginia corrections employees have been suspended in response to an image of them performing a Nazi salute.

From our friends at FiveThirtyEight:

A FiveThirtyEight politics chat askes the question, How Did The Democrats End Up With A 2020 Field So White And Male?

Doff your cap:

Adoption hearings are often bureaucratic affairs involving testimony and paperwork. But a young boy from East Grand Rapids, Michigan, was so excited about his adoption day that he invited his entire kindergarten class to his adoption hearing.

Michael Clark Jr.'s classmates filled up courtroom and gave sweet testimonies about how much they love their friend. And the whole class cheered as Michael’s new parents became his forever parents.