Pinchas was born in Haifa 1918 to Ya’acov Shimshon and Chaya Dvora nee Blau, a stable, traditional family. His parents, fifth generation in Israel, were born in Safed and dealt in commerce. He studied at  ‘Netsach-Yisrael’ school,  then  the ‘Tiferet Yisrael’ Yeshiva, in Hadar-Hacarmel. When studies ended, he opened a Private Investigations office in Haifa. He joined Etzel 1938 and worked in the Intelligence department, greatly assisted by input from his office. With the 1940 split in Etzel, Pinchas followed Yair and became a member of Lehi. He was arrested that year at his uncle’s in Haifa and was jailed in Akko  then transferred to Mizra Detention Camp, where all Etzel/ Lehi members were held. Pinchas observed his religion at prison, always attending synagogue on Sabbath. He was studying languages and Law, and excelled in athletic activities. After Yitzchak Shamir and Eliyahu Giladi escaped from Mizra, the remaining prisoners were transferred to Latrun. On arrival, the Lehi men – including Pinchas – began tunnelling an escape route to the outside. During the night of November 1, 1943, twenty Lehi members escaped through the tunnel, arriving safely in Tel-Aviv.  Pinchas lost his way in the dark; underwent  difficulties, and using his wits managed to rejoin his comrades later in Tel-Aviv. He was immediately put into action in Department 6 (Intelligence). Shortly after, he was transferred to the Haifa branch. He was arrested again 1944, and exiled to  prison camp in Africa, with the sixth group of 12 Hebrew prisoners from Israel. He was imprisoned in the camps of Carthago  Sudan, Sambal  Eritrea, and Gilgil Kenya. In March  1948 he was returned to Israel, detained at Atlit prison camp until Declaration of Independence, and  released. He spent seven years in prison. Following the assassination of Count Bernadotte  Lehi members throughout the country, including Pinchas, were arrested; he was detained at Jalameh Prison until the general amnesty. After his release, he began working in commerce.

In 1952 he married Aliza. They have two children and thirteen grandchildren. They lived in Jerusalem. Pinchas passed away on July 27, 1998, and was brought to rest on Har-Hamenuchot, Jerusalem.