The week after Adam Lanza went on a shooting spree in Sandy Hook Elementary School in Newtown, Conn., a federal judge in Philadelphia denied immunity to a police officer in a case where his son stole his department-issued gun to kill his estranged girlfriend.

“This decision by Judge Joyner was made shortly after Sandy Hook,” Suzanne McDonough told a three-judge panel of the U.S. Court of Appeals for the Third Circuit. “I think that’s why it was made.”

McDonough, of Holsten & Associates in Media, Pa., is representing John Michael, the father of the man who killed his girlfriend, since he was sued by her family under a state-created danger theory.

The case was before the Third Circuit on interlocutory appeal, with Michael challenging U.S. District Judge J. Curtis Joyner of the Eastern District of Pennsylvania’s decision to deny him either qualified or statutory immunity.

In denying Michael’s claim for qualified immunity, Joyner had said, “An officer is liable under the state-created danger doctrine when the officer is aware of the risk of grave harm and is responsible, at least in part, for creating that risk.”

Joyner also denied Michael’s statutory immunity claim, brought under the Child Safety Lock Act of 2005, which immunizes legal owners of firearms from liability for illegal acts committed with their weapons if they have used a safety device to render it “inoperable.”

The meaning and interpretation of that word garnered significant debate during oral argument.

Joyner had decided that “Congress’ use of the term ‘inoperable’ is puzzling.”

“A strict reading of the term ‘inoperable’ would make it impossible for the immunity provision to apply at all; a third party, no matter how determined, cannot fire a truly ‘inoperable’ firearm and could, therefore, cause no harm which might result in liability from which the statute may immunize him or her. But a loose reading of the term ‘inoperable’ does not accord with the word’s plain meaning,” he had said in his opinion, concluding that the term was ambiguous.

In this case, Michael had brought his gun home from work, as was encouraged by the police department, put a safety lock on it, hidden the key, removed the bullets and put them elsewhere, then locked the deadbolt on his bedroom door.

Frank DiMeo of Rosen, Schafer & DiMeo in Philadelphia is representing Andrea Arrington’s family and told the appeals court that the question of the gun’s operability should be determined by a jury.

“The statute says ‘inoperable by device’ … doesn’t that anticipate that someone was using a gun lock, as was done here?” Judge Marjorie O. Rendell asked. “How could a jury decide, in a way that a judge wouldn’t overturn it, that this was not sufficient inoperability? What is ambiguous?”

“That the gun was actually used,” DiMeo answered.

“Why is this a question for a jury at all?” Judge Kent A. Jordan asked. “If the question is, ‘what does that word mean in a statute,’ isn’t that exactly the kind of question we call a question of law?”

Earlier, Jordan had asked McDonough for her best argument under the state-created danger doctrine.

Referring to Michael, she said, “It would be that even if you assume that he did something wrong, he never did anything that could arise to the level of shocking the conscience … deliberate indifference.”

Then, engaging with DiMeo, who had advanced an argument that Michael had acted with deliberate indifference, Jordan asked, “What’s deliberately indifferent about bringing your service revolver home like you have done for your whole career, putting a trigger lock on it, hiding the key, hiding the bullets, deadbolting the door, hiding the key to the deadbolt — what in that series of events should lead a rational jury, if they ever got it, or a judge looking at it from a qualified immunity standpoint, to say, ‘Now that’s deliberately indifferent?’”

“What shocks the conscience here is that he brought that gun home knowing that his son would have undisturbed access to that house,” DiMeo said, listing various examples of unstable behavior from Aaron Michael’s past, including the domestic incidents that had led to the restraining order that Arrington had gotten against him.

In July 2009, when John Michael went on vacation with his police gun locked in his bedroom, his son, Aaron Michael, broke down the door, searched the Internet for instructions on how to use a gun, shot and killed Arrington, and was later shot and killed himself during a run-in with police.

On the panel with Rendell and Jordan was First Circuit Senior Judge Kermit V. Lipez, sitting by designation.

Saranac Hale Spencer can be contacted at 215-557-2449 or Follow her on Twitter @SSpencerTLI.