Judy Woodruff:

It was one year ago this week that a gunman opened fire at Marjory Stoneman Douglas High School in Parkland, Florida, killing 17 students and educators.

Since that time, there has been a push for securing schools, for arming teachers, and for tightening gun laws. Schools and districts are also increasingly turning to anonymous tip lines to encourage students to report any concerns they have.

The latest state to jump on board is Pennsylvania.

Special correspondent Lisa Stark of our partner Education Week went to see how it's working for our weekly education segment, Making the Grade.