Mitch Daniels has signed a law expanding the state's castle doctrine. This law specifically states that if a police officer enters a house illegally, the badge does not protect him/her from the castle doctrine. This means that if police officers don't show warrants and before entering houses, the occupants are allowed use lethal force just like if any other armed person broke in. The reason why this law was established was because of a state supreme court decision that allowing that would violate the Fourth Amendment.
I don't have any idea why allowing citizens to protect themselves from illegal search and seizure would violate the Constitutional amendment protecting us from illegal search and seizure.
A little less than a year ago, a Marine Corps veteran name Jose Guerena was shot by SWAT in Arizona in what was apparently a drug raid without a warrant on the wrong house. He had heard heavily-armed people enter his house without identifying themselves, so he grabbed his AR-15 rifle and investigated, fearing that it would be related to his wife's family's murder by a Mexican drug gang. He did not point his rifle at the officers or even disengage the safety, but five officers shot 71 rounds of ammunition in seven seconds, hitting him 22 times and paramedics were denied permission to aid him, so he bled to death in four minutes..