Sen. Markwayne Mullin promised on Capitol Hill this week that if he is confirmed as DHS secretary, he will direct U.S. agents to use judicial warrants, signed by a judge, whenever possible except for in extreme circumstances.

Judicial warrants are legally distinct from administrative warrants, which are generally issued and signed by federal agencies. Judicial warrants are signed by a judge and usually explain specific details about what may be searched and when.

Experts say judicial warrants help ensure proper oversight and protection of rights.

"One of the main reasons for the existence of the 4th Amendment was to have a disinterested objective observer be required to sign off before law enforcement violates really important rights, whether arresting you are searching your home or whatever," said Ronald Allen, a professor at the Northwestern Pritzker School of Law. "As one Supreme Court opinion said, we don't want the people that are engaged in a competitive process of ferreting out crime to be making these decisions as to whether there's adequate information to violate — it may not be a violation, but to ensure some of these important rights."

Experts also said in instances where agents enter someone's home without the proper warrant and then there is a case of damage or death, victims or family members may not have the proper legal recourse in court. Or it could take some time for people to get some sort of remedy against the government or those agents.

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The issue of judicial warrants is in the spotlight following nationwide protests against the Trump administration's immigration policies and the conduct of ICE and other Homeland Security agencies. Images went viral of ICE agents going into communities and homes to arrest people.

Georgetown Law professor Louis Michael Seidman says that did a lot to steer how agents' conduct was received.

"What matters is public opinion and popular opposition," Seidmand said. "So what got DHS to back off of this was not some ruling by some judge. It was very brave and committed people who took to the streets in freezing weather to protest this. That's why they backed off. If there's a remedy, the remedy not legal. It is popular opposition."

There remain certain exceptions to the rules surrounding judicial warrants, such as cases of invitation from residents or emergency circumstances.