Aliaksandr Kapshul is a former legal adviser at the Naftan and Polymir oil refineries. He spoke openly about the problems in Belarus. In 2020, he was fired for taking part in the strike. He then began to help independent trade union activists, defending them in court pro bono.

In September 2021, he was on a private trip to Russia. When the arrests of trade union activists began, Aliaksandr decided to leave Belarus. He went to Moscow with the intention to travel to Warsaw. On the train, his documents were checked by the Federal Security Service of the Russian Federation. When he realised that he would have been arrested on his arrival in Moscow, he jumped off the train. Aliaksandr broke his leg and dislocated his arm, but managed to make it to the Ukrainian border. When crossing the Russian-Ukrainian border legally, he was detained, then taken to Belarus and handed over to KGB officers.

Kapshul was charged with 'high treason' and participation in an extremist formation' in the case involving several employees of Belarusian major enterprises who supported the local strikes and were members of the Rabochy Rukh labor rights group in 2020. That initiative was labeled as "extremist" on September 2021. He was also charged with 'illegal actions related to firearms': it turned out that when his summer house was searched, old cartridges were found, but there were no weapons.

On November 9, 2022, the Homieĺ Regional Court began the trial of the Rabochy Rukh case involving ten political prisoners. At the trial, all the defendants refused to plead guilty to treason and creating an extremist formation. They also refused to testify.

Aliaksandr Kapshul has been on hunger strike for 51 days in protest against the violations perpetrated in the Homiel pre-trial detention centre. During the first few days, he was not even given water.

On 17 February 2023, the Homiel Regional Court issued a verdict in the case of the Rabochy Rukh labour rights group. Aliaksandr Kapshul was sentenced to 15 years in prison. He was then subjected to a more severe regime.

Aliaksandr is married and has two minor children. In May 2022, his mother died and he wasn't allowed to attend the funeral.