The ruling could have an effect on Indiana's immigration law.
The Supreme Court upheld one portion of the law that allows law enforcement to ask people for identification, or legal papers.
The Indiana law, signed last year, is modeled after Arizona's law, which opens the door for legal challenges here.
Today's Supreme Court ruling on Arizona's immigration law could have a major impact on Indiana's law.
Justices struck down three provisions; regarding immigrants carrying registration papers and seeking employment, and allowing arrests without warrants.
However, they allowed status checks, which means police can ask for anyone's identification or legal papers.
Last year, Governor Mitch Daniels signed Indiana's immigration law, which is nearly the same as Arizona's.
"They really had the ability to make some bad things happen. Sometimes things are not defined enough, or the concept may be ok, but the execution could really go wrong," says immigration attorney Jerri Mead.
Mead says the ruling shows immigration reform is too complex to be addressed by individual states.
"It has to be federal because it's got to be even across the board. And I can honestly tell you, practicing this area of law, that it's not," mead says.
Civil rights expert Cathy Serrano says the decision allows challenges to Indiana's law.
The American Civil Liberties Union of Indiana challenged the law last year, and say they will do so again.
"I think you're going to find the Indiana legislatures are going to be look at this decision, and they're going to be looking at the Indiana law, and seeing which provisions might be affected by that," says Serrano.
Indiana Attorney General Greg Zoeller said in a statement today they've already started reviewing the decision, and will provide guidance to the legislature.
Serrano told me that even if a person is not here legally, they can still file a civil rights lawsuit based on how they were treated.
She told me that under the prior Arizona, and also Indiana law, that would have been a possibility.