The man charged with setting fire to the Pennsylvania governor’s mansion staged the attack because he believed Gov. Josh Shapiro’s stance on the war in Gaza was leading to the deaths of Palestinians, according to a police search warrant made public on Wednesday.

After the arson attack, the suspect, Cody A. Balmer, identified himself on a 911 call and said that Mr. Shapiro, who is Jewish, “needs to know that he ‘will not take part in his plans for what he wants to do to the Palestinian people,’” according to the search warrant.

“Balmer continues saying he needs to stop having my friends killed, and ‘our people have been put through too much by that monster,’” an apparent reference to Mr. Shapiro, though it was not spelled out in the warrant.

Mr. Balmer, who had been treated for mental illness in the past and was facing a separate charge of having assaulted his family in an earlier case, said at the end of the call: “you know where to find me. I’m not hiding and I will confess to everything that I’ve done.”

In an interview with the police after he turned himself in to the police, Mr. Balmer “admitted to harboring hatred” of Mr. Shapiro and said that he would have “beaten him with his hammer” had he run into him on the night of the attack at the mansion, according to an affidavit filed in the case.

With the search warrant, the Pennsylvania State Police seized four smartphones, a laptop and an external hard drive that are being examined by investigators.

Mr. Balmer, 38, has been charged with attempted murder and other offenses in connection with the attack, which left two rooms of the mansion badly burned. No one was injured in the attack.

Shortly before the attack, Mr. Shapiro had entertained dozens of friends for dinner to celebrate the first night of Passover, a Jewish holiday.