‘This is not a drill’ — School gun violence and the terror it creates have riveted America again since a gunman shot and killed 17 people last month at a high school in Parkland, Florida. But with each heinous attack successfully carried out, there have been many more scores of threats in schools across the country. And while thankfully no one dies because of a threat, fake or foiled attacks terrorize students, too. In the past month, since the Parkland shooting, there have been more than 465 bomb or gun threats or both, according to the Educators School Safety Network, a nonprofit that provides school safety training.

Trump rallies — President Donald Trump’s campaign rallies were associated with a rise in violence when they came to town, according to a study published Friday. A city that hosted a Trump rally saw an average of 2.3 more assaults on the day of the event than on a typical day, according to the study, led by researchers at the University of Pennsylvania and published in the journal Epidemiology. One explanation the researchers offered: the aggressive mood on display by Trump and his followers had spread through “social contagion.”

Kickbacks for fentanyl prescriptions — In March of 2013, a sales manager for Insys Therapeutics, the maker of Subsys, a form of the highly addictive painkiller fentanyl, told Manhattan doctor Gordon Freedman he would receive more money if he increased the number of new patients he prescribed Subys. “Got it,” Freedman replied, according to authorities, and within a year he had become one of the country’s top prescribers of the painkiller drug. The exchange was in a federal indictment unsealed Friday in Manhattan, charging Freedman and four other New York doctors with participating in a bribery and kickback scheme that prosecutors said sought to increase the drug company’s sales and preyed on unwitting patients.

Gun regulators and the NRA — For years, the National Rifle Association has used its sway in Washington to preserve the limited capacity of the Bureau of Alcohol, Tobacco, Firearms and Explosives. It benefits the NRA to have a smaller ATF in charge of gun regulation, one senior bureau official acknowledged, rather than a larger, more politically powerful agency such as the FBI that can more effectively demand additional resources from Capitol Hill. Now, the ATF is on the verge of a crisis. The agency is facing a staffing shortage, is set to lose its tobacco and alcohol enforcement authorities, and President Donald Trump has yet to nominate a director to oversee the agency.

‘Rewilding’ missing carnivores — Since their reintroduction — or rewilding — to Yellowstone and Idaho in the 1990s, gray wolves have done so well that they’re reclaiming other parts of the northern Rockies, and tidied up explosive deer and elk populations, which had eaten valleys barren. That helped bring back vegetation, controlling erosion and helping the return of birds, beavers and other animals. Oregon State University ecologist William Ripple and a postdoctoral researcher now suggest in a paper published Wednesday that with proper attention and care, the “rewilding” of lions, tigers, bears and other species of large carnivores could result in ecological benefits like those seen with gray wolves.

Trump’s North Korea meeting — The CIA has emerged as the primary player in President Donald Trump’s audacious diplomatic opening to North Korea, several officials said Friday, conducting back-channel communications and taking a major role in planning Trump’s coming meeting with Kim Jong Un, the country’s ruler. The White House’s decision to use intelligence, rather than diplomatic, channels in communicating with the North Koreans speaks to the influence of Mike Pompeo, the CIA director whom Trump chose this week to replace Secretary of State Rex Tillerson. It also reflects the State Department’s diminished role in preparing for the riskiest encounter between a U.S. president and a foreign leader in many years.

Putin’s re-election — With the hours slipping away until Russia’s presidential election Sunday, Valentina Aristova, a Communist Party die-hard in Nizhny Novgorod, rose before sunrise to hand out campaign literature. Aristova reflected on the two twists in what is expected to be a romp by President Vladimir Putin to a fourth presidential term. First, support for Putin in large cities has been uneven or even declining in favor of Pavel Grudinin, a wealthy farmer. Second, efforts to ensure participation have not altered expectations for a mediocre showing given the lack of mystery. “Putin fears being shamed before the whole world if the turnout is below the baseboard,” Aristova said.

Muslim lawmakers get threatening packages — British police are investigating threatening packages received this week by Muslim members of Parliament that contained a letter calling for “Punish a Muslim Day” and, in some cases, a noxious substance. Sajid Javid, the secretary for housing, communities and local government in Prime Minister Theresa May’s Cabinet, was among those who received the letter. Javid posted on Twitter a photo of the letter sent to him Thursday.

Zuma corruption charges — In a severe legal blow to Jacob Zuma, South Africa’s former president, national prosecutors announced Friday that they would reinstate corruption charges against him in a case related to a multibillion-dollar arms deal in the late 1990s. Shaun Abrahams, South Africa’s chief prosecutor, said there were “reasonable prospects of a successful prosecution” of Zuma. The announcement was the latest — although not likely the final — chapter in a long-running corruption case that nearly derailed Zuma’s bid for the presidency and tarnished the image of South Africa’s governing African National Congress. The deal under scrutiny laid the seeds of a culture of graft that has flourished in recent years.

When Xi Speaks, Chinese officials jump — After China’s president, Xi Jinping, ordered Beijing to cut its population, his protégé ordered the bulldozing of the homes of tens of thousands of migrants. After Xi told northern Chinese provinces to cut smog, cadres junked home heaters and stoves, leaving residents shivering. These days when Xi speaks, officials from the top of the Communist Party to the lowest village committees snap to unflinching attention. As these recent cases suggest, Xi’s daunting power may undercut effective policy or provoke public ire when lower officials scramble over each other to meet or exceed expectations, often leading to overreach and disarray.

Polar bear to get star treatment — When the polar bear was born just before Christmas in Scotland — the first in Britain in 25 years — zoologists could confirm the occasion only because of the high-pitched sounds coming from the mother’s den. The cub did not emerge for weeks, but now the tiny polar bear is moving around “confidently,” the zoo says, and will get the star treatment in a documentary set to air Sunday on Channel 4. The mother, Victoria, is one of three adult polar bears at the Royal Zoological Society of Scotland’s Highland Wildlife Park. She mated with Arktos, one of two males at the park, and gave birth to the cub.

In Russia, gold falls from the sky — Yakutsk, a city 5,000 miles from Moscow where temperatures can plummet to minus 85 degrees Fahrenheit, is not the sort of place where people spend winter nights searching the bushes by torch light. But it is not every day that 3.4 tons of precious metals fall out of the sky. The unusual scene unfolded this week after a door on a Soviet-era cargo plane sprang open on takeoff. The bars were doré, a semi-pure alloy of gold and silver. One widely shared image showed a screenshot from a ride-sharing app: “Yakutsk airport,” read the request. “Need a Toyota Probox-style estate car. Three 200 kilograms sacks. URGENT!!! Payment: a half-kilo of gold.”