Cell phone companies operating in Minnesota must assist in missing person investigations under a new state law that takes effect Sunday.
The law is called the Kelsey Smith Act, named for a Kansas teenager who disappeared three years ago.
Her parents spent several days trying to convince a cell phone company to track Kelsey's phone. Her body was finally found when the company agreed.
Minnesota State Senator Yvonne Prettner Solon of Duluth sponsored the law and said it will ensure a delay like that doesn't happen again.
"National law says they may give this information," Solon said. "We have changed that to they must under certain circumstances -- when there's threat of harm or death to an individual -- they must give that information."
Solon said cell phone companies are capable of immediately complying with the new state law.