As my colleagues Donna St. George and Lyndsey Layton reported Tuesday, parents across the country are asking questions about school security following the fatal shooting of 26 students and staff at Sandy Hook Elementary in Newtown, Conn.

A student pauses after placing flowers at a memorial at the entrance to Newtown High School in Newtown, Conn., Dec. 18, 2012. (Lucas Jackson/Reuters)

Susan Messina, the parent of a student at Deal Middle School in Northwest, said she was shocked to learn that her daughter could not recall ever doing a lockdown drill during her nine years in D.C. public schools.

“Children need practice in remaining silent and away from doors and windows,” Messina wrote in an e-mail. “In the unthinkable event of an armed killer, one child making noise could mean death to an entire classroom. Having a plan on paper, with no practice, seems useless.”

DCPS trains all principals in crisis response and encourages them to conduct lockdown drills among other emergency-preparedness drills, said school system spokeswoman Melissa Salmanowitz.

Many principals do conduct lockdown drills, Salmanowitz said, but they are not required to; nor are they required to report whether they conduct them to the central office.

Over the summer, all DCPS principals received active-shooter training. Central office administrators reminded principals of that training Friday and sent them a copy of training materials.

All DCPS schools have at least one school security officer, and many schools have metal detectors and other security systems, such as alarms and cameras.

“We’re really confident in our security systems,” Salmanowitz said. “These scenarios obviously draw bright lights on the importance of keeping security protocols tight and relying on them in times of crisis.”