The two teenagers arrested on suspicion of plotting a mass school shooting in South Pasadena were not armed, but police said Tuesday that they were still in the beginning stages of their plan.
South Pasadena Police Chief Art Miller told reporters at a news conference that the two youths, ages 16 and 17, had researched weaponry, explosives and methods for disarming people. Officials did not find weapons after serving search warrants at the boys' homes Monday, but, Miller said, it "doesn't mean they weren't going to have guns later on."
"It's like anything else, we could've stopped the plot at the beginning, a quarter or halfway in," he said.
The teenagers -- who were arrested Monday and have not been identified -- wanted to kill "as many people as possible" and told investigators that they were willing to die in a shootout with police, Miller added.
They had also "very cold-heartedly" discussed their plans with each other online, Miller said.
"This was at the very beginning of their plot to create a massacre," he said.
Police launched the around-the-clock investigation Thursday based on a tip about a possible school shooting plot that was relayed to administrators at South Pasadena High School, he said.
The investigation that ensued included "Internet surveillance" during which they were observed "very cold-heartedly" discussing their plans with each other online, Miller added.
Investigators believe they have a motive, but did not elaborate. Police officials planned to turn the results of their ongoing investigation over to county prosecutors for review on Tuesday.
The FBI was also assisting with the forensic investigation, which included computers taken from the boys' homes.
News of the purported plot shocked many people in this close-knit community, including Deb McCurdy, who will be president of the parent-teacher association next year.
"We're stunned, but relieved the systems in place worked," she said.