DENVER -- Colorado is taking the lead in the battle to keep sex offender registration laws on the books.

This fall the U.S Supreme Court will determine the constitutionality of an Alaskan law requiring sexual offenders to be registered with local police.

The 9th Circuit Court of Appeals struck down Alaska's registry as unconstitutional and double punishment.

Colorado Attorney General Ken Salazar said Friday that Colorado will work with 42 other states to make sure the Alaska law and other sex offender laws around the country are upheld.

"If the United States Supreme Court were to decide that the Alaska registration and notification system is unconstitutional, than many parts of our law here in Colorado would fall by the wayside as unconstitutional," Salazar said.

Salazar and 42 other state attorneys filed a brief on Friday with the Supreme Court supporting Alaska's challenge to the appellate court ruling.

Colorado's registry names 7,647 sex offenders. Of those, pictures and personal information of 166 offenders are posted on the Internet. An additional 175 sex offenders are posted on the Internet for failing to register.

Alaska's law, modeled after New Jersey's pioneering "Megan's Law," allows the public to track known sex offenders. Like Colorado law, it requires lifetime registration with quarterly updates. Both states also post the names and pictures of some sex offenders on the Internet.

Salazar said the goal of the registries is preventive, not punitive. The registry lets law enforcement agencies and neighbors know where sex offenders are in the community, he said.

The possibility that Colorado's online sex offender registry could be tossed out has many people concerned that they won't be able to learn about sexual offenders living in their neighborhoods, 7NEWS reported.

Many people 7NEWS talked to feel it's their right to know where those offenders are living.

"It's a matter of having information so that they can make wise decisions," parent Pat Hoddock said. "I do believe in privacy but if this is a site that is proven constitutional, that people can use. It needs to be there."

Angela Smith, who cares for kids in her neighborhood, logged on to the site for the first time on Friday. After typing in her zip code, she discovered that there are sex offenders living near her.

"You would hope that there wouldn't be (any). I feel that I should be a little more careful with my nieces and nephew," Smith said.

More Information:

Colorado's Sex Offender Registry (Search option may be busy at times, and come up as an error page. We suggest you keep trying.)