Photo: Los Angeles Police Chief Charlie Beck heads to a news conference at Hale Middle School on Thursday. (Anne Cusack / Los Angeles Times)

LAPD Chief Charlie Beck and others on Thursday strongly defended the decision to lock down 7 square miles of the west San Fernando Valley as they searched for a gunman who shot a police officer a day earlier near El Camino Real High School in Woodland Hills

"I know the parents are upset, but it would be nothing compared to what they would feel if their children were needlessly exposed to an armed gunman. Those kids' safety is No. 1," Beck said. "This guy had shown total disregard for public safety and the community by shooting an armed police officer who was doing his job," Beck said.

Assistant Police Chief Earl Paysinger added: "We would be irresponsible in a fresh and unfolding tactical situation to expose young people to the threat of an armed gunman who has already demonstrated his intention to commit violence."

Deputy Chief Kirk Albanese said the size of the dragnet zone around the shooting site was due to several factors. He said police initially had a limited description of the suspect, who was armed and running through the neighborhood. The LAPD also got several 911 calls reporting possible prowlers in the area. Police charted the calls and set the dragnet accordingly, Albanese said, not knowing whether the calls involved the gunman.

The suspect eluded the massive dragnet set up after the shooting near El Camino Real. The LAPD closed off a large swath of the area as more than 300 officers searched for the gunman. More than 9,000 students spent hours locked inside their schools.