Washington ? The Supreme Court on Wednesday debated whether a murder victim’s family prejudiced the trial of an accused killer by wearing buttons to court bearing a picture of the slain man.

The justices waded into issues of defendants’ rights, struggling with the question of whether the buttons visible to the jury in Mathew Musladin’s case denied him a fair trial or were a harmless expression of grief. The state of California is seeking to reinstate Musladin’s conviction, which was thrown out by the 9th U.S. Circuit Court of Appeals.

Some of the justices seemed uncertain about how to proceed. There is “a pretty darn good argument” the buttons risked the defendant’s right to a fair trial, Justice David Souter said. At the same time, Souter asked, “What … do I make of the fact that not one single court has ever reached that conclusion as a constitutional matter?” He questioned where such a line would be drawn.

“What if the three buttons worn by the family of murder victim Tom Studer had said ‘Hang Musladin,’ would you say there was not sufficiently clear law from this court to find that practice unconstitutional?” Souter asked.

“What would you do with banners? … Signs, placards?” asked Justice Anthony Kennedy. Or mourning family members dressed in black, wondered Chief Justice John Roberts.

Scalia said the message of the buttons in the Musladin case did not point to the defendant as the killer, the same conclusion reached by the trial judge.

Musladin said he acted in self-defense in the shooting death of Studer, the fiance of Musladin’s estranged wife. Studer was shot twice, the second time as he lay under his truck in an attempt to escape the gunfire.

Musladin was sentenced to 32 years to life in prison.

The case is Carey vs. Musladin, No. 05-785. A decision is expected by July.