Yaacov was born in Jerusalem in 1932 to Rosa and David. He grew up in the Zikhron Yosef neighborhood in a traditional home. He studied in a Talmud Torah and in the Kol Israel Haverim School. Once he completed his studies, he became a stonemason. This was a common occupation for Lehi members in Jerusalem because of the explosive materials used. Yaacov found his way to the underground. He was known for being brave and for his great satisfaction from his work with Lehi.

When the War of Independence broke out, he was called up for full duty, and he took part in mayn operations in besieged Jerusalem and its environs. The last battle he fought in was after the first truce, attacking the “Tin Shack” in Beit Mazmil (now Kiryat HaYovel). He fell alongside four other Lehi members, on July 27,1948. He was only sixteen.

In Elnakam, Ezra Yakhin writes about him (p. 301): “And Amnon — my Amnon, he was one of the boys in my cell. Amnon begged and begged me to take him back into the ranks of the fighters. He turned the world upside down. ‘You, you’ll see… You’ll see how good I am,’ he said after he was insubordinate in his wildness. He said it, and he proved it. He never stopped proving it; with all his soul and with all his power, he proved it. Until he fell among the slain.”

Yaacov was buried in the Sanhedria Cemetery; and on 20 September 1951, he was re-interred at the Mt. Herzl Military Cemetery in Jerusalem.