The Senate General Laws Committee began a two-part hearing Tuesday on the measure that would declare certain federal gun control policies “null and void.” Agents enforcing them could spend a year in jail, be fined up to $1,000 and face other civil penalties.

Courts have consistently ruled that states cannot nullify federal laws, but that hasn’t stopped them from trying or ignoring them anyway. Last year, a federal appeals court struck down a 2009 Montana law that sought to prohibit federal regulation of guns that were manufactured in the state and remained within its borders.

But the nullification aspect of the Missouri bill didn’t garner the attention of the panel or the witnesses testifying about the legislation. Instead, a provision that would prevent health care personnel from being required to ask or document whether a patient owns a gun drew the most discussion.

“No matter what it is, I should be able to document it,” said Sen. Rob Schaaf, a St. Joseph Republican and the Senate’s only licensed physician. “I don’t want to think if I’m stepping afoul of some esoteric law.”

Schaaf said he was concerned about regulating what a physician can ask a patient or include in a medical record. The Missouri Academy of Family Physicians and the Missouri Association of Osteopathic Physicians echoed Schaaf’s sentiments and said the legislation could lead physicians to unknowingly break state law when talking with patients.

The bill’s sponsor said he was open-minded about changing the measure’s language to meet the physicians’ concerns, but added that the provision is necessary to protect a patient’s privacy when it comes to gun ownership.

“There is always this quandary when one amendment wants to trump the other, but we try to strike a balance,” said Sen. Brian Nieves, R-Washington.

The Republican-led Legislature began pushing for a comprehensive pro-gun bill after President Barack Obama called for expanded background checks and a ban on assault weapons. Its attempt to enact a bill to nullify federal gun control laws failed last year after Republicans could not get enough votes to override Democratic Gov. Jay Nixon’s veto.

Like last year’s version, the legislation would also allow designated school personnel to carry concealed weapons in buildings. Another provision would let holders of concealed gun permits carry firearms openly, even in municipalities with ordinances banning open carry. It would also lower the minimum age to get a concealed weapons permit to 19, down from 21.

But Nieves’ bill is less specific about which federal laws it seeks to nullify. It removes references the 1934 and 1968 gun control acts while keeping generic references to fees, registration and tracking policies that “have a chilling effect on the purchase or ownership” of guns and ammunition by law-abiding citizens.

The panel did not vote on the proposal and is planning to hold another public hearing next week.