Sean Penn’s CORE praises Los Angeles’ guardian angels — those on the ground administering COVID-19 tests — in a new PSA that reiterates that “testing saves lives.”

On March 30th, CORE (Community Organized Relief Effort) opened its first coronavirus testing site in Los Angeles; since that time, CORE now oversees 15 sites, including 12 in California, two in Atlanta and a mobile site in Detroit. Their team of 120 staff members and 300 volunteers have thus far administered 70,000 tests as of May 6th.

The “Guardians” PSA — narrated by actor Edward James Olmos — features a visual tapestry of near-desolate Los Angeles, “the City of Angels,” where only essential workers and CORE volunteers remain on the streets.

“Angels come in many ways. You might not recognize their faces, don’t know who they are,” Olmos says in the PSA over footage of the testers at work. “From downtown to LAX, from South Central to PCH, watching over us. Protecting us. Let them know that we see them.”

“CORE’s role is twofold” First, to have direct impact on the health of each and every individual we can reach. But secondly, it is our singular role in modeling government/civilian NGO partnerships that, in replication can test all Americans and re-test all Americans as long as science and medicine demands to develop a vaccine,” Penn tells Rolling Stone.

“The importance of testing begins with identifying those who may transmit the virus. Hospitalization is not necessarily required for those who test positive. Until, or unless those positive begin to experience respiratory issues, they may convalesce at home, but they must immediately isolate. The other contribution we make when we submit to being tested is a contribution to the national surveillance piece,” Penn added. “We are ALL responsible to fight this virus. Give us robust defense production, then, our great country of Republicans, Democrats, Asians, blacks, whites, browns, men, women WILL do our part. This is a moment where our president can establish a glorious legacy. It’s got to be NOW.”

The “Guardians” PSA was directed by Samuel Bayer, who helmed Nirvana’s iconic “Smells Like Teen Spirit” video. “I’ve known Sean for a number of years. When the pandemic hit, I knew his organization CORE would be fighting the good fight,” Bayer tells Rolling Stone. “I called him up and asked if I could contribute something.”

“I saw firsthand all the brave, selfless and vital work the CORE volunteers were doing during a very difficult time,” he added. “I thought maybe if I could document the anguish that Los Angeles is feeling right now and the hope that I saw at those testing facilities, maybe a film could touch people and make a difference.”

Asked what his vision was for the PSA, Bayer replies, “I wanted to create something real and honest. A snapshot, a small piece of the story. It sure isn’t about me, there’s nothing heroic in making a film about this pandemic. I saw real heroes. That’s the story I tried to tell.”

“Sam Bayer so beautifully captures our most essential message,” Penn says. “The hope to disarm this beast is volunteerism. I am a full tilt believer in a policy of mandatory service, but when I see CORE’s volunteers serving… that one makes me weep.”

CORE plans on additional sites opening around the country, including Navajo Nation, New Orleans, Georgia and North Carolina.