A regional court in Verden found Klette guilty of aggravated robbery, gun law violations and other crimes linked to robberies on supermarkets and cash-in-transit vans carried out alongside two other former RAF members who remain at large.
The case garnered nationwide attention when Klette was arrested at her Berlin flat in February 2024, where she had lived for years under a different name.
Klette, 67, had gone into hiding by the time the RAF - also known as the Baader-Meinhof Group from its founding members, Andreas Baader and Ulrike Meinhof - disbanded in 1998.
She managed to evade arrest for some 30 years, leading a normal life in Berlin's trendy Kreuzberg neighbourhood, where she reportedly regularly attended capoeira classes, a type of Afro-Brazilian martial arts dance.
Klette went on trial in March 2025, charged with attempted murder, illegal possession of firearms and aggravated robbery, allegedly committed alongside accomplices Burkhard Garweg and Ernst-Volker Staub, two other former RAF members.
Garweg and Staub are still on the run, with Klette believed to have tipped off Garweg by text when she was arrested.
The trio is said to have stolen over $US2.3 milllion between 1999 and 2016 to finance their life in hiding, robbing cash-in-transit vans and supermarkets in northern and western Germany.
Investigators uncovered weapons, ammunition, a fake RPG, forged IDs, wigs, gold and $US279,000 in cash at Klette's flat.
Prosecutors had sought a 15-year prison sentence for Klette.
The court found Klette guilty of aggravated robbery, attempted aggravated robbery, violations of gun laws, kidnapping for ransom, and aggravated extortion.
When the presiding judge announced the sentence, supporters of the defendant protested the verdict with loud boos and chanted "Freedom for Daniela".
Klette's defence team had maintained the evidence presented in court did not prove she had been involved in the robberies.
Attorney Lukas Theune had called for a suspended sentence, citing the weapons found in his client's flat which he admitted constituted a violation of the Weapons Act.
The RAF was a far-left militant group in the former West Germany founded in 1970. It was active until 1998, carrying out a series of bombings, assassinations, kidnappings, bank robberies and shoot-outs with police.
More than 30 people were killed in Germany in RAF attacks.
The proceedings in Verden, near Bremen, only involved suspected offences committed after the RAF disbanded in 1998.
Klette has also been accused of involvement in three RAF attacks between 1990 and 1993, which could result in separate charges, including attempted murder.
