Finnish volunteer jailed over fatal crash in Ukraine suffers health problems after alleged detention center assault, lawyer says
A Finnish volunteer serving a prison sentence over a fatal traffic accident in Ukraine has been receiving medical care in a pretrial detention facility for more than six months following an alleged assault by another detainee, his lawyer told Hromadske.
Roope Mikael Mustonen, a volunteer from Helsinki, was convicted over a May 2025 crash that killed an officer of Ukraine's Security Service (SBU).
His lawyer, Mykhailo Tarasenko, said Mustonen was hospitalized in January 2026 after being beaten by a cellmate without provocation. According to Tarasenko, his client continues to experience health problems and remains in the detention center's medical unit.
Hromadske could not independently verify the circumstances of the alleged assault from the lawyer's account.
Mustonen has been held in custody since May 2025, without the option of release on bail.
Asked whether his client had become disillusioned with Ukraine, Tarasenko replied, "Of course he has, and he is not the only one."
The lawyer said Mustonen's case had prompted criticism in Finland, including claims that his treatment raised questions about Ukraine's readiness for European Union membership.
Tarasenko also alleged that the position of the victim's widow, a Ukrainian judge, had influenced Mustonen's detention. The lawyer said representatives of the widow had made this clear to him.
The allegation of improper influence has not been independently substantiated in the information available to Hromadske.
Fatal crash and prison sentence
In May 2025, Mustonen, then 33, was driving a Volkswagen Transporter van from Kharkiv toward Kyiv while transporting humanitarian supplies and equipment, including materials for training drone operators.
According to Mustonen's account, a black Toyota SUV was stopped partly on the roadway, with its hazard lights on. He said he saw the vehicle but failed to notice its driver, who was standing near a wheel.
Mustonen struck the man, who died later in hospital. The victim was subsequently identified as an SBU officer.
Police determined that Mustonen had been traveling at between 100 and 150 kilometers per hour.
In January 2026, a court in Ukraine's Poltava region sentenced Mustonen to six years in prison. An appeals court later reduced the sentence to four years.
The courts also ordered financial compensation for the victim's family, including monthly payments to his children until they reach adulthood.
Tarasenko said a transfer to Finland to serve the remainder of Mustonen's sentence was a possibility, but no such transfer has been confirmed.
Mustonen's father has traveled to Ukraine to visit him.