As a high school student, Papečkys was imprisoned by the Tsarist police for publishing an illegal newspaper Mokinių draugas.

Papečkys was the prosecutor in the trial of the 117 members of the Polish Military Organisation who organized a coup against the Lithuanian government.

Juozas Papečkys was born on 1 January 1890 in the Puskepuriai [lt] village of the Suwalki Governorate to a peasant family.

Papečkys noted in his autobiography that since the third grade, he participated in the distribution of illegal books and patriotic proclamations, and organized village youth and schoolchildren, preparing lectures and performances for them.

[1] In 1908, Papečkys began contributing articles to Vilniaus žinios, Lietuvos ūkininkas, and other Lithuanians newspapers.

Due to the efforts of the State Duma representative and lawyer Andrius Bulota, they were acquitted and allowed to return to the gymnasium.

[4] In addition to Russian and Lithuanian, Papečkys knew the Polish, German, French, Italian, and Latvian languages.

[5] In 1916, Papečkys was mobilized into the Russian Imperial Army as a private and assigned to the 57th Reserve Infantry Regiment in Tver.

[7] In 1918, Papečkys moved to Pyatigorsk in the northern Caucasus where he joined a committee, organized by Juozas Avižonis, that provided aid to the Lithuanians war refugees.

[6] When Pyatigorsk became the capital of the Terek Soviet Republic, Avižonis and Papečkys organized a commissariat for Lithuanian refugees.

[12] Due to the martial law in effect in Lithuania, the military court also handled criminal and civil cases.

[10] Papečkys gained recognition after prosecuting 117 members of the Polish Military Organisation who organized a coup against the Lithuanian government.

[3] He also lectured at the War School of Kaunas and Higher Officers' Courses (1921–1926), contributed articles to various newspapers, and was chairman of the Lithuanian Military Studies Society (1925–1926).

[15] Papečkys worked as a private lawyer[23] until January 1929, when he became a member of the State Council of Lithuania, eventually becoming its deputy chairman in August 1938.

[25] When the State Council was liquidated after the Soviet occupation of Lithuania in June 1940, Papečkys obtained a job as a consultant at the People's Commissariat of Justice.

Papečkys was transported via Starobelsk to a gulag camp near Sosva in the Sverdlovsk Oblast (part of Sevurallag [ru]).

[27] However, NKVD accused 15 Lithuanians (including Papečkys and Voldemaras Vytautas Čarneckis [lt]) of organizing a "counter-revolutionary" group that prepared for an armed mutiny inside the gulag.

Teklė, not having learned of her husband's fate, died in 1953 in Yakutsk, while their two daughters successfully returned to Lithuania in 1957.