A California prosecutor is taking legal action against parents of children in e-bike crashes.

Orange County District Attorney Todd Spitzer has more than two dozen open investigations.

His office has already charged four parents.

One of them is the mother of a 14-year-old who is accused of killing a pedestrian.

Other areas are doing different things.

New York City warned online sellers about illegal e-bikes after a 17-year-old died.

New Jersey now requires riders to be at least 15 and have a license.

California has no minimum age for lower-powered bikes.

Some parents and supporters say these steps are not enough.

Monica Stafford, whose daughter broke her skull, asked for one set of national rules.

She said officials are in a "Wild West of laws."

Cycling groups say many dangerous vehicles are really e-motorcycles sold as e-bikes.

Researchers say injuries from e-bikes are worse than from regular bikes.

Dr. John Austin said patients are often younger and not wearing helmets.

Parents like Sharon Franke say safety begins at home, with research and training.

She said balancing fun and safety is "overwhelming right now."