By Jamie Ross and Hannah Jewell  Email Listen to this briefing Good morning. It’s Monday, May 20, and if you’re planning to stay in an Airbnb soon, here are six red flags to watch out for. Now let’s catch up from the weekend. Iran’s president died in a helicopter crash yesterday, state media said. What happened? Nine people including President Ebrahim Raisi and Iran’s foreign minister were killed when their chopper crashed in thick fog. Who was he? Raisi, 63, was a hard-liner who cracked down on dissent as Iran’s second-highest official. His death comes at a time of turmoil in the Middle East. The latest: Mohammad Mokhber, Iran’s first vice president, will become acting president. Read this story            Michael Cohen will testify again today in Donald Trump’s hush money trial. What to expect: It may be the former Trump fixer’s final day on the witness stand. He has given prosecutors the testimony they hoped for, but Trump’s lawyers attacked his credibility. The end could be near: The first criminal trial of a former U.S. president could finish up this week. It appears increasingly unlikely that Trump will testify. Want to dig deeper? Our reporters covering the New York trial shared this behind-the-scenes look. Read this story            President Biden told students he’s pushing for an immediate cease-fire in Gaza. Yesterday: Biden said he’s working “around-the-clock” on a deal to release Israeli hostages and get aid into Gaza in his speech to graduating seniors at Morehouse College. The reaction: A handful of students and faculty members at the historically Black college turned their backs during the speech in protest of Biden’s support of Israel’s war. Read this story              Sean “Diddy” Combs apologized over a video of him attacking his then-girlfriend. The details: The footage showed the rap mogul grabbing, pushing and kicking singer Cassie Ventura in a hotel in 2016. Yesterday, Combs said his actions were “inexcusable.” Zooming out: Five lawsuits have been filed against Combs in recent months, accusing him of decades-long patterns of sex trafficking and sexual and physical assault. Read this story            Mosquitoes are swarming Houston after powerful storms. What to know: Residents have reported record numbers of the bloodsucking pests after severe rains hit much of Texas, although it’s hard to fully count an insect population. This could become normal: As the world gets warmer — and in many areas, wetter — scientists expect more places will become perfect mosquito breeding grounds. Read this story            ADVERTISEMENT     Xander Schauffele won the PGA Championship for his first major title. How it played out: The 30-year-old broke through a crowded leader boardand held off Bryson DeChambeau yesterday in the final round at Valhalla Golf Club in Louisville. The other, stranger story: Scottie Scheffler, the world’s No. 1 player, was arrested Friday morning as he tried to enter Valhalla, but he returned to play. He is set to be arraigned tomorrow. Read this story            An ancient site is challenging the timeline of when humans reached the Americas. Casts of tools and sharp-edged stones found at Parsons Island, Md. (Michael Robinson Chávez/The Washington Post) What to know: Since 2013, scientists have unearthed human-made objects on an eroding island in the Chesapeake Bay. They say the oldest dates back more than 22,000 years. It’s controversial: That’s thousands of years earlier than when most scientists think humans arrived in the Americas. This finding — and others— could threaten that theory. Read this story