Two teenagers suspected of plotting a mass shooting at a suburban Los Angeles high school denied charges Wednesday that they made criminal threats against another boy.
The teens weren't specifically charged in connection with the suspected school shooting plot.
However, additional charges may be filed as investigators uncover more evidence, South Pasadena Police Sgt. Brian Solinsky said.
Solinsky said a tip from a community member led school officials to alert police last week about the suspected shooting plan.
The boys were arrested Monday after detectives monitored their online activity and unraveled the alleged plot to target three school staffers and kill as many students as possible, police said.
Police say the pair were researching automatic firearms, handguns, knives, explosives and tactical techniques.
Prosecutors say the teens shared their intent with another boy and on Saturday threatened to kill him. Further details weren't immediately released.
The pair didn't have any weapons or a date for an attack, police said.
Family members of both teens apologized to the community and the school Wednesday.
The 17-year-old suspect's father told KCAL-TV that he was upset and disappointed by the allegations, and he thanked the person who tipped off authorities. The 16-year-old's stepfather, meanwhile, said his son had no intention of actually harming people he loves.
The Associated Press is not naming the parents, because doing so could reveal the identities of the underage suspects.
Police Chief Arthur Miller has said his officers saved lives by thwarting the attack in the town of about 25,000 people known for its quality schools and community involvement in education.
The FBI joined the investigation to help search for evidence on computers seized from the boys' homes.
Classes start again Thursday in the quaint San Gabriel Valley suburb about 6 miles from downtown Los Angeles. Police plan to have a larger presence than usual on campus for the first day of school.