5 Things to Know This Morning

— -- Your look at the five biggest and most buzz-worthy stories of the morning.

1. ‘Dancing With the Stars’ 2015 Finale: And the Winner of the Mirror Ball Trophy Is ...

After 10 weeks of grueling practice and competition and one final round of competition, Rumer Willis was declared the winner of season 20 of ABC’s “Dancing With the Stars” Tuesday, beating out Noah Galloway and Riker Lynch.

The scores for the fusion challenge, the dance assignment the competitors received after Monday's show and performed on the finale, were added to the scores they received from that show, where Willis and Lynch had been tied for first place with Galloway in second.

The judges' scores were combined with viewers' votes, with the winner being the dancer with the highest combined scores.

2. Waco, Texas, Shooting: Take a Look Inside Biker Gang Culture

Following a deadly Waco, Texas biker gang brawl over the weekend, a pair of experts in biker gangs paint a picture of a culture revolving around territory, turf wars and the underlying sense that violence could break out at any moment.

Charles Falco, who was a confidential informant for the Bureau of Alcohol, Tobacco, Firearms and Explosives, said gangs "will conduct violence at the drop of a hat if they think someone is disrespecting who they are, their territory."

Members of as many as five biker gangs gathered at Twin Peaks Restaurant in the Central Texas Market Place Sunday to discuss their differences, according to Waco Police Sgt. Patrick Swanton. But then an "additional biker gang that was not invited to this meeting showed up," Swanton said. "Hence, what we were calling somewhat of a turf war, if you will."

3. Four Cancer Charities Accused of Pocketing $187M in Donations

Four cancer charities and their operators have been charged with shamefully bilking $187 million from consumers, the Federal Trade Commission announced today.

According to the FTC, which worked in conjunction with all 50 states, donors were told that their donations would help cancer patients.

"Those were outright lies," said Jessica Rich of the FTC's Bureau of Consumer Protection.

4. California Single Mom Fights for Right to Die

Christy O'Donnell doesn't want to die, but she doesn't want to spend the rest of her good days fearing the painful death that awaits her as she struggles with terminal cancer, she said.

"The most likely way that I’m going to die with the lung cancer is that my left lung will fill with fluid, I’ll start drowning in my own fluid," she says in a YouTube video posted this week by Compassion and Choices, the nonprofit aid-in-dying group that Brittany Maynard worked with before ending her life last fall. "If I get to a hospital, they'll very painfully put a tube in. They’ll drain the fluid from my lung, only to patch me up, send me home and wait until the next time my lung fills up with fluid. And they'll continue to repeat that process and drowning painfully until I die."

5. David Letterman and Bill Murray Share Cake and Memories

What a perfect time for cake.

Guest Bill Murray celebrated David Letterman’s penultimate episode on late-night television Tuesday by bursting out of a cake, himself covered in frosting and batter. Following a hug, the host and guest conducted their final segment together caked in the sugary mess, reflecting on the old, good times and swigging from a bottle of vodka.

“Late Show With David Letterman” spent Tuesday’s episode celebrating the icons.