His family moved to Israel in July 1950, and he grew up in Musrara, Jerusalem, a neighborhood predominantly populated by recent Mizrahi and Sephardi immigrants.

[2] In the 1960s, Shemesh founded and edited a daily community newspaper, which he operated illegally without a permit, publishing sports and Sephardi human interest stories.

Shemesh joined the organization immediately, and would soon become its primary ideologue and the editor of its publications[3] from 1971 until 1977, when those duties were taken over by Charlie Biton and Saadia Marciano.

Shemesh participated in charitable aid organizations, co-founding Zoharim village, the first drug addiction recovery center in Israel.

As a result of his experiences working on that project, Shemesh alongside other Black Panthers began a campaign to demand general amnesty for prison inmates.

He was quoted in 1973 as saying that "[Mizrahi's] strongest bond is with the poor and oppressed in the Middle East", and that the Black Panthers' goals were to "[seek] an alliance with the Arabs and forming an economic bloc to counter the influences of both US and the USSR."