| |
| Here are the week's top stories, and a look ahead. |
 Mark Lambie/The El Paso Times, via Associated Press |
| 1. Two mass shootings in less than 24 hours. |
| A gunman opened fire on Saturday in a crowded Walmart store in El Paso, a majority-Hispanic border city, killing at least 20 people and injuring dozens. One suspect, a white man in his 20s, is in custody. |
| Law enforcement officials are studying an anti-immigrant manifesto that was posted online shortly before the attack to determine whether it was written by the gunman. |
| And in Dayton, Ohio, at least nine people were killed and 16 were wounded in a shooting early Sunday in an entertainment district. Officers shot and killed the gunman. |
| The shootings this weekend come less than a week after a gunman killed three people and wounded 13 others at a garlic festival in Gilroy, Calif. In all, there have been at least 32 mass shootings, defined as three or more killings in a single episode, in the U.S. this year. |
| ____ |
 Erin Kirkland for The New York Times |
| 2. As the 2020 election gears are set in motion, this weekend we're looking at a crucial voting bloc: black voters. |
| Democratic leaders say African-Americans are deeply engaged in this election, but President Trump is also courting them with Facebook ads, spending far more on digital advertising than his Democratic challengers. Whether black voters like Mark Greer of Detroit, above, are motivated or discouraged may well determine Mr. Trump's political future. |
| After two rounds of debates, 24 Democratic candidates are still running for president. There's little incentive to drop out right now, but August will be crucial. Only eight candidates have qualified for the next debate in September. Here's a quick look at what else happened in the 2020 presidential race this week. |
| Have you been keeping up with the headlines? Test your knowledge with our news quiz. And here's the front page of our Sunday paper, the Sunday Review from Opinion and our crossword puzzles. |
| ____ |
 Drew Angerer/Getty Images |
| 3. Global trade tensions escalated again this week after President Trump announced new tariffs on another $300 billion worth of Chinese imports. |
| The announcement rattled investors: The S&P 500 recorded its worst week of the year, exacerbating fears of a global slowdown. Above, the New York Stock Exchange this week. The European Central Bank is preparing to try to bolster the eurozone economy, while the Fed cut interest rates this week for the first time in over a decade to get ahead of possible downturns. |
| The tariffs, which are slated to take effect Sept. 1, would increase the prices of everyday items. Here's what to expect. |
| ____ |
 Lam Yik Fei for The New York Times |
| 4. Unrest in Hong Kong continues. |
| Thousands of antigovernment demonstrators are out again today, the second of three straight days of planned civil disobedience. On Saturday, protesters and police officers clashed in a sprawling march that resulted in more than 20 arrests as officials in Hong Kong, a semiautonomous Chinese city, come under more pressure from Beijing to restore order. |
| A general strike scheduled for Monday could be even more disruptive. |
| And in Moscow, thousands of riot police officers flooded the city to curb planned protests calling for fair elections. Hundreds were arrested. The protests came as the Russian authorities announced they had opened a criminal investigation into an anticorruption organization. |
| ____ |
 Pedro Pardo/Agence France-Presse — Getty Images |
| 5. Overflowing toilets, bedbugs and extreme heat: This is what life is like inside one of Mexico's migrant detention centers. |
| From April to June, the Mexican authorities detained about 73,400 migrants, more than double the number detained during the first three months of the year. The spike means Mexico's detention centers, like the Siglo XXI detention center in Tapachula, above, have at times reached triple, quadruple and even quintuple their capacity. |
| The Trump administration's "Remain in Mexico" policy has helped decrease the number of migrants trying to cross the U.S. border, but it has also created a crisis in Mexico's detention centers that critics say is subjecting adults and children to inhumane conditions. |
| Here's how the immigration initiative is also forcing many asylum seekers stuck in Mexico to navigate the court system without representation. |
| ____ |
 Ben Brewer/Reuters |
| 6. "When it comes to power, no one dares to stand up to the pork industry, not even the U.S. government." |
| That's coming from a former chief veterinarian of the Agriculture Department's Food Safety and Inspection Service. In the latest in our series about drug-resistant infections, we reconstructed a salmonella outbreak caused by pork in Washington State in 2015. |
| Medical investigators urgently hunted for the source of the outbreak. What they found instead was a powerful industry whose interests are blocking scientists and investigators from getting the information they need to combat the problem. |
| ____ |
 Simon Fraser/Science Source |
| 7. Alzheimer's disease is difficult to diagnose. A new blood test may one day make it easier to predict the disease, even in people without symptoms. |
| The test measures beta amyloid protein in the blood, the protein that is a hallmark of Alzheimer's. The new blood test was not only more accurate than a brain scan, researchers announced this week, it also identified patients with amyloid deposits earlier. |
| The test is still years away from use in doctors' offices. Should you get a brain scan if you have memory problems? One expert warned of "unintended downsides," including overuse of only modestly effective medications. |
| ____ |
 Andrew Scrivani for The New York Times |
| 8. And now, a recipe that will change how you cook. |
| Perfecting the technique for a seasonal risotto, like this tomato dish, opens up a year's worth of meals, David Tanis writes. It's an easy and versatile meal. Here are five other dishes for the week ahead. |
| When it comes to sherry, most people either love it or hate it. But its unusual method of production and pungent flavorings make it a wine worth savoring, our critic writes. |
| ____ |
 Yael Malka for The New York Times |
| 9. "People should have more options." |
| That was a maxim for the two dozen non-monogamous people we interviewed about polyamory. For them, more partners meant more exploration and more pleasure. But it's not always easy. |
| "There is no single model that suits everyone," said Effy Blue, a relationship coach in Brooklyn. Above, from left: Thomas Kavanagh, who is dating Ms. Blue, and Andrew Sparksfire and Beth Sparksfire, who are married. Ms. Blue and Mr. Sparksfire also date; the relationship structure is called a "z." |
| ____ |
 Tim Gruber for The New York Times |
| 10. Finally, dig into one of our Best Weekend Reads. |
| We checked in with the staff of The Warroad Pioneer as the Minnesota newspaper ended its 121-year run, remembered the Broadway giant Hal Prince and visited two friends in Columbia, Mo., as they roller skated through summer. |
| For more on what to read, watch and listen to, check out the latest small-screen recommendations from Watching; these 11 new books our editors liked; our music critics' latest playlist; and our Metropolitan Diary, which has readers' tales of life in New York City. |
| And don't forget to watch the latest episode of "The Weekly," about young climate activists, which airs tonight on FX at 10 p.m. Eastern, and on Hulu on Monday. |
| It's August, and the peaches are perfect. Have a sweet week. |
| Your Weekend Briefing is published Sundays at 6 a.m. Eastern. |
| You can sign up here to get our Morning Briefings by email in the Australian, Asian, European or American morning, or here to receive the Evening Briefing on U.S. weeknights. |
| Browse our full range of Times newsletters here. |
| What did you like? What do you want to see here? Let us know at briefing@nytimes.com. |
