Two cops patrolling a neighborhood, a 13-year-old boy with a toy gun and a tragedy.

Here in Sonoma County, where a deputy sheriff shot Andy Lopez to death, people are asking why and, equally important, how to ensure it never happens again. But it already did.

Andy Lopez was again.

A little less than three years ago, people asked these questions in Los Angeles after police shot a 13-year-old boy holding a pellet gun. Rohayent Gomez survived, but he was left paralyzed.

He was playing on a street with two other teenagers, firing their pellet guns at one another. The boys ran when a police car pulled over.

Officer Victor Abarca spotted Gomez hiding behind a bus. He shined a flashlight on him and ordered him to surrender. Abarca saw the pellet gun and fired once, striking Gomez in the chest.

Police described the toy as "indistinguishable" from a Beretta handgun. It did, however, have the orange tip required by federal law for toy firearms. The tip was missing from the AK-47 replica BB gun carried by Andy Lopez. We don't know if it was removed on purpose or broken. Either way, it may have cost Andy his life.

In Los Angeles, Abarca was cleared of any criminal wrongdoing, but a jury returned a $24 million civil verdict against the Police Department.

After the shooting, Los Angeles police Chief Charlie Beck got behind legislation to add<QA0>

BB guns and pellet guns to a state law requiring replica firearms sold in California to be brightly colored or translucent, so it's obvious at a glance that they aren't the real thing.

"We have seen far too much heartbreak involving these types of realistic-looking guns that are labeled as toys," Beck told the Los Angeles Times.

Predictably, it was too much for Second Amendment groups and firearms retailers. They lobbied against the bill, arguing, among other things, that it was an overreaction to the Los Angeles shooting and that it could give police a false sense of security, potentially endangering their safety. In the Assembly, the bill was watered down, with the requirement for bright colors for BB guns replaced by permission to enact local regulations stricter than state law. The bill still died in committee.

After the Santa Rosa shooting, Sen. Kevin DeLeon, D-Los Angeles, said he will try again.

We don't know if that law would have saved Andy Lopez. His BB gun may be more than two years old, and a California law can't stop people from buying realistic-looking toy weapons in Arizona or Nevada or any other state with different laws. But, as a University of South Carolina criminology professor pointed out, "If it's a pink bubble gum gun and an obvious fake to most, then there is no reason to shoot."

The death of Andy Lopez raises an array of questions that must be addressed by investigators, law enforcement officials and public policymakers.

Some of these issues, such as appropriate police tactics, are quite complicated. Here's a question that's pretty simple: Should cops making split-second decisions about their safety and the safety of the public be forced to distinguish between real firearms and harmless toys? The answer is as obvious as a bright orange BB gun.