LOS ANGELES — Since the arrests of a dozen students here on suspicion of sex-related crimes, members of the Venice High School community have been doing some soul-searching about what they could have done to prevent the assaults — some of which the police said took place on campus — and what they can do to try to ensure that nothing similar happens again.

“We’re trying to determine how much of this, if any of this, could have been prevented with more security,” said Steve Zimmer, the Los Angeles school board member whose district includes Venice High School. “That’s really unclear right now.”

According to the Los Angeles Police Department, 14 boys from Venice High School, ages 14 through 17, were involved in the sex acts with two girls from the school described as in their midteens, beginning in December 2013, and continuing until as recently as this month. Twelve of the boys have been arrested — eight of them on campus during the school day last Friday. The police say they have been unable to find the other two.

Some of the sex acts were consensual and some were not, the police said, but consensual sex with a minor is also a crime in California, and the boys could be charged with various offenses.