Students walk the halls at Senn High School in Chicago. Photo: Joshua Lott / The Washington Post via Getty Images

"As schools around the U.S. look for ways to impose tougher security measures, ... they don't have to look further than urban districts such as Detroit, Chicago, Los Angeles and New York that installed metal detectors and other security in the 1980s and 1990s to combat gang and drug violence," AP reports. "Security experts believe these measures have made urban districts less prone to mass shootings, which have mostly occurred in suburban and rural districts."

Why it matters: "Officials in some suburban and rural school districts are now considering detectors as they rethink their security plans after the shooting at Marjory Stoneman Douglas High School."

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Biden releases 2019 tax returns ahead of debate

Photo: Alex Wong/Getty Images

Joe Biden's campaign released his 2019 tax returns on Tuesday, showing that he and his wife, Jill, paid nearly $300,000 in federal taxes last year.

Why it matters: The release, timed just hours before the first presidential debate, comes days after a bombshell New York Times report said that President Trump paid only $750 in federal taxes in 2016 and 2017. Biden's team is hoping to make the tax contrast a sticking point during their showdown.

Updated 2 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 2:15 p.m. ET: 33,454,037 — Total deaths: 1,003,571 — Total recoveries: 23,204,219Map.
  2. U.S.: Total confirmed cases as of 2:15 p.m. ET: 7,165,067 — Total deaths: 205,476 — Total recoveries: 2,794,608 — Total tests: 102,342,416Map.
  3. Health: Americans won't take Trump's word on the vaccine, Axios-Ipsos poll finds.
  4. States: NYC's coronavirus positivity rate spikes to highest since June.
  5. Sports: Tennessee Titans close facility amid NFL's first coronavirus outbreak.
  6. World: U.K. beats previous record for new coronavirus cases.

NYC's coronavirus positivity rate spikes to highest since June

New York Mayor Bill de Blasio. Photo: Noam Galai/Getty Images

New York City's coronavirus positivity rate has ticked up to 3.25%, its highest since June, Mayor Bill de Blasio said at a news conference on Tuesday.

Why it matters: The jump — from 1.93% on Monday — came on the first day that public elementary classrooms reopened in the city after months of closures, but guidelines state that all public schools will have to shut if the citywide seven-day positivity rate stays above 3%.