[citation needed] "Tommy", the eldest son of Eduardo Joson of Quezon, Nueva Ecija, a former guerilla officer who later served as provincial governor,[3][4] and Araceli Noriel, was born on May 10, 1948, in Santo Domingo.

[7] As governor, he initiated the "Nueva Ecija 2000", supporting programs including on agriculture through establishing a provincial fruits and vegetable seed center.

[8][9][10][11] Joson was the chairperson of his family's Bagong Lakas ng Nueva Ecija (Balane) when he nominated former fourth district representative Rodolfo Antonino as the party's candidate in the 2016 gubernatorial elections;[12] the family decided to support the latter's candidacy as they did not join for the first time in 56 years.

[13] Tomas III, his younger brother Mariano Cristino, and two others were implicated in an alleged raid in a provincial jail in April 1990 wherein a prison guard who is a Constabulary enlisted man was killed in a shootout between the two, along with their bodyguards, and Quibuyen family members.

[6][14] The two were charged as principal suspects[15][16] in the ambush of Tomas' gubernatorial rival, then Cabanatuan mayor Honorato Perez Sr. of the administration's Lakas–NUCD, who was shot dead along with his bodyguard in Talavera on April 22, 1995.

[19][a] Tomas III and Mariano Cristino ("Boyet"),[17] then mayor of Quezon,[15] both re-electionists under Balane–Laban ng Demokratikong Pilipino–Nationalist People's Coalition, later withdrew their candidacies.

[19] In 1998, while in detention, Tomas III and Mariano Cristino ran and were elected governor,[9][20] against Perez's widow,[21] and Quezon mayor respectively.

[11][22] In April 2018, the Supreme Court decided to exclude Tomas III from liability in relation to alleged irregular award of ₱155 million to a private contractor for the construction of a hotel in the province.

[23][24] In July 2019, Tomas III, as well as former mayors of Quezon (his nephew, Eduardo Basilio) and Bongabon, were convicted by the Sandiganbayan of three counts of graft and was to serve at least 18 years in jail, in relation to his donation of service vehicles to these municipalities in 2007, which found violated the Local Government Code.