They are pieces of evidence the jurors didn’t get to see, the bloody, shredded shirts that Jonathan Rizzo and Philip McCloskey were wearing at the time they were stabbed to death in July 2001.

Thirteen years ago, US District Judge Mark L. Wolf refused to show them to jurors in the death penalty trial of Gary Lee Sampson, finding they were so graphic they would pose a “risk of unfair prejudice’’ toward the death penalty. Sampson, who had admitted to the murders, was sentenced to death anyway, but the jury’s verdict was overturned on appeal.

Now, in advance of Sampson’s new death penalty trial in September, US District Judge Leo T. Sorokin said Friday he wants to see the shirts himself, reconsidering prosecutors’ arguments that the shirts speak to the “heinous, cruel, and depraved’’ nature of his crime, making him deserving of death.

Sorokin gave lawyers for Sampson a Sept. 12 deadline to respond, and ordered the government to make the shirts available for his inspection. The shirts were cut from the bodies of Sampson’s victims, and preserved in plexiglass.

“The victims’ shirts . . . are unquestionably relevant to Sampson’s intent, as well as the heinous, cruel, and depraved nature of the murders,’’ prosecutors argued in court records Thursday.

Sampson, now 56, had admitted to the carjacking and killing of Rizzo, 19, and McCloskey, 69, during a violent spree in July 2001. He also killed Robert “Eli’’ Whitney, 58, that same week in New Hampshire.

A jury agreed after a 2003 trial to sentence him to death, but Wolf vacated that decision after finding that one of the jurors had lied during a screening process.

The question of admitting the shirts as evidence resulted in one of the loudest arguments in the original trial. Wolf initially planned to show them to jurors, agreeing they speak to the heinous nature of the crime — one of the factors prosecutors want to prove in seeking the death penalty, and which requires evidence of torture or physical abuse — but he later reversed that decision, saying instead that it could be overly prejudicial.

“An honest balancing of the competing factors at this point should operate to exclude the shirts,’’ the judge said, quoting Shakespeare’s “The Tragedy of Julius Caesar’’ to raise concerns that the shirt would “incite revenge.’’

Wolf also questioned whether jurors would be influenced by the reactions of the families of Sampson’s victims in the courtroom, and whether the shirts would become “powerful and immediate symbols of the victims and the brutality of their murders.’’

“I do find that the danger of unfair prejudice in terms of overwhelming emotions and rational response in the context of all the other evidence and the way the case has evolved outweighs the probative value,’’ the judge said.

The families of Sampson’s victims had long criticized Wolf’s handling of the 2003 trial, and point to his refusal to admit the shirts as evidence, and his concerns over how the families would respond, as one of their key disputes.

“We thought this was very important evidence in our case,’’ Michael Rizzo, the father of Jonathan Rizzo, said in an interview Friday, adding that he was glad that the question is at least being reconsidered.

Prosecutors argued that other court decisions have upheld the admissibility of blood-stained clothing as evidence since the Sampson trial, and that such evidence is routinely introduced in local murder trials.

The prosecutors also noted that the clothing of two of the victims of the Boston Marathon bombings — Krystle Campbell and Martin Richard — was introduced in the death penalty trial of Dzhokhar Tsarnaev.

“The vicious, brutal nature of a defendant’s conduct is not itself sufficient to justify a complete exclusion of evidence tending to show the defendant engaged in those acts,’’ prosecutors argued.

Milton J. Valencia can be reached at milton.valencia@globe.com. Follow him on Twitter @miltonvalencia.