The man charged with murdering Shinzo Abe sent a letter to a critic of the Unification Church signaling his intention to kill the former prime minister prior to the shooting earlier this month, the recipient said Sunday.

The letter shows the strong resentment that the alleged assailant, Tetsuya Yamagami, 41, felt toward the church, with which he believed Abe had ties. Police appear to be aware of the letter.

Yamagami sent the letter apparently from Okayama Prefecture to the recipient's address in another part of the Chugoku region.

The male recipient, whose identity has been withheld, made blog posts criticizing the Family Federation for World Peace and Unification, widely known as the Unification Church.

Yamagami has told investigators that his mother's donations to the church ruined his family's finances. His uncle says they totaled about ¥100 million ($720,000).

In the letter, Yamagami said he "felt bitter" toward Abe, who he described as "one of the most influential sympathizers of the Unification Church in the real world," but that the former leader "was not his original enemy."

Abe was shot on July 8 when delivering a stump speech on a street in Nara.

Yamagami was arrested at the scene, where police found a homemade gun, and he was later sent to prosecutors on suspicion of murder.