10 things you need to know today: May 15, 2021

Despite Israeli officials and Hamas signaling openness to a cease-fire on Friday, violence continued early Saturday when an Israeli air raid in Gaza City killed at least 10 Palestinians, reportedly mostly children, in a refugee camp. It appears to be the deadliest individual strike since the latest phase of the conflict broke out last week, The Associated Press reports. Later, an airstrike flattened a tower in Gaza, which housed both Al Jazeera and AP's offices. People were reportedly notified to evacuate beforehand. Hamas said it was firing rockets at Tel Aviv in return. More than 130 people have been killed in Gaza, as well as eight people in Israel, since the violence began. Hady Amr, an envoy from the United States, arrived in Israel on Friday and is scheduled to join Israeli and Palestinians officials for de-escalation talks in Jerusalem on Saturday.

State and local officials across the country are "scrambling" to adjust masking and social distancing guidelines and messaging, after the Centers for Disease Control and Prevention said that it was safe for people who have been fully vaccinated against COVID-19 to go without a mask or practicing social distancing in most situations, indoors or outdoors. Though existing mask policies vary greatly by city and state, officials spent much of Friday determining how to implement the CDC's new guidelines, or whether they should continue to advise masking. As of Friday, 36 percent of adults in the U.S. are fully vaccinated against COVID-19, while 64 percent are not. One of the major points of confusion for local officials in implementing the new guideline is how to determine who is vaccinated.

Rep. Elise Stefanik (R-N.Y.) has officially replaced Rep. Liz Cheney (R-Wyo.) as the new chair of the House Republican Conference. Republicans on Friday voted to elect Stefanik to Cheney's former post after Cheney was ousted from that position this week for criticizing former President Donald Trump over his false claims of widespread voter fraud in the 2020 presidential election. Stefanik, meanwhile, is a Trump ally who has backed numerous false election claims he has made, and the former president endorsed her for the leadership position. She thanked Trump for his support after the vote, calling him a "critical part of our Republican team." Cheney has vowed to continue her fight against Trump and ensure he doesn't serve another term as president.

Joel Greenberg, Rep. Matt Gaetz's (R-Fla.) former confidant, has agreed to cooperate with prosecutors and admitted to sex trafficking a minor, The New York Times reports. Greenberg, a former Florida tax collector, reached a deal with prosecutors to plead guilty to six federal charges against him, including sex trafficking of a child. He admitted that he and others paid a 17-year-old girl for sex, saying that he "introduced the minor to other adult men, who engaged in commercial sex acts" with her. Prosecutors reportedly say they have evidence corroborating Greenberg's admissions. Gaetz has been facing an investigation into whether he had sex with a 17-year-old girl and violated sex trafficking laws. Though Greenberg didn't implicate Gaetz by name in the new filings, according to the Times, he "has told investigators that Mr. Gaetz had sex with the girl and knew that she was being paid."

The China National Space Administration successfully landed its Zhurong rover on Mars on Saturday, state media reports, making China the third country after the United States and Soviet Union to touch down on the Red Planet (the 1971 Soviet mission failed shortly after landing.) Zhurong will eventually be deployed from the lander for a three-month mission in search of evidence of ancient life on Mars' surface, much like the multiple NASA rovers that have scoured the planet over the years, including Perseverance, which made its way to Earth's neighbor earlier this year. The landing is considered a major advancement for China's space program.

Walmart, Sam's Club, Costco, Trader Joe's, and Publix on Friday were among the first major retailers to announce that shoppers fully vaccinated against COVID-19 would no longer have to wear masks in their stores, unless required by state or local law. The change in company policies comes after the Centers for Disease Control and Prevention updated its guidelines earlier this week to say that it's safe for vaccinated people to go maskless indoors in most cases. People who have not received their shots will still need to wear face coverings, though it's not clear how the stores will verify who has been vaccinated. Several other major retailers, including Apple and Target, are keeping their mask requirements in place for now, but said they could update the policies soon.

South Carolina officials on Friday released hours of police body-camera footage, which shows a Charleston County sheriff's deputy repeatedly tasing Jamal Sutherland, a 31-year-old Black man, before he died in custody in January. Sutherland was arrested after a fight broke out at the psychiatric facility were he was receiving mental health treatment, and the next morning two deputies were trying to remove him from his cell for a bond hearing when one deployed a taser. Sutherland was pronounced dead over an hour later, and the county coroner's office said the cause of death was an "excited state with adverse pharmacotherapeutic effect during subdual process." Charleston County Sheriff Kristin Graziano said she has implemented changes to bond hearing protocol, including allowing detainees to waive their appearances at hearings and adding technology to allow for remote hearings. She also promised to improve the department's response to mental health needs.

Rep. Alexandria Ocasio-Cortez (D-N.Y.) described Rep. Marjorie Taylor Greene (R-Ga.) as a "deeply unwell" person who "clearly needs some help" as video of Greene harassing her office in 2019 resurfaced. CNN on Friday reported on a since-deleted Facebook Live video showing Greene outside of Ocasio-Cortez's locked office door taunting her staff through a mailbox slot during a Capitol Hill visit in Feb. 2019, before she was elected to Congress. Earlier this week, Greene "aggressively confronted" Ocasio-Cortez as she exited the House chamber, shouting at her in an incident House Speaker Nancy Pelosi (D-Calif.) described as a "verbal assault" that should "probably" be investigated by the House Ethics Committee. "Her fixation has lasted for several years now," Ocasio-Cortez said Friday. "At this point, I think the depth of that unwellness has raised concerns for other members as well."

Ebrahim Raisi, Iran's judiciary chief, registered Saturday as a candidate in the country's upcoming presidential election. The cleric is considered a hard-liner, as opposed to the more moderate incumbent President Hassan Rouhani, and a close ally of Supreme Leader Ayatollah Ali Khamenei. His ties with Khamenei, his role in a televised anti-corruption campaign, and the fact that Iran's hard-liners are considered to hold an edge, may make Raisi the favorite going into the race, The Associated Press reports. In a statement Saturday, Raisi said he would fight "poverty and corruption, humiliation and discrimination" and run a "popular administration for a powerful Iran" if elected. Raisi has never publicly acknowledged his role on a panel involved in the mass execution of thousands of prisoners at the end of the Iran-Iraq War in 1988.

Medina Spirit, the winner of the Kentucky Derby, has been cleared to run in the Preakness Stakes, the second leg of horse racing's Triple Crown, on Saturday after passing three prerace drug tests. Medina Spirit, trained by Bob Baffert, failed a post-Derby drug test, which led to Baffert's suspension from Churchill Downs and skepticism about whether the horse would run at Pimlico Race Course in Baltimore this weekend. Medina Spirit's stablemate and fellow Baffert trainee, Concert Tour, also passed the three tests agreed upon by Baffert and Maryland racing officials. The race will begin at 6:47 p.m. ET on Saturday. As of Friday night, Midnight Bourbon had supplanted Medina Spirit as the betting favorite.