BISMARCK, N.D. (AP) — North Dakota Republican Gov. Doug Burgum has signed a measure that establishes protections for confidential drug informants.

The action Monday comes more than three years after 20-year-old college student Andrew Sadek was found dead in a river with a bullet in his head and a backpack of rocks tied to his body.

His parents, Tammy and John Sadek, have lobbied lawmakers to pass legislation so that informants can be better informed of their legal options to understand the risks they may be taking.

The bill clarifies the rights of people offered the role as a confidential drug informant, including their right to an attorney.

It also requires a written agreement with an informant. Law enforcement agencies also must undergo training before using them.