The case related to two massacres, the first committed on November 3, 1991 when a group of masked soldiers burst into a party in the Lima suburb of Barrios Altos, killing 15 people, including an eight-year-old boy.
Several months later, nine La Cantuta university students and their professor were rounded up by the same "La Colina" squad, taken to a deserted area of the city and executed with shots to the back of their heads.
The lawyer also asked for an annulment of Fujimori's conviction in the kidnapping of a journalist and a businessman, both critics of his government, in 1992, also because he claimed there was not enough evidence to prove that the former president had ordered the abductions.
Given Fujimori's age and ill-health, the 25-year sentence would likely mean the former president would spend the rest of his life in prison.
However, his daughter Keiko Fujimori has vowed to pardon him if she is sucessful in her bid for the presidency in 2011.
Fujimori's political downfall began in 2000 when a video of Vladimiro Montesinos, his security chief, was broadcast on television, showing him buying off an opposition politician.
Soon after, Fujimori fled to Asia and resigned via fax from a Tokyo hotel. Congress refused to accept his resignation and instead voted to sack him and ban him from public office for 10 years.
In 2005, Fujimori, who was trying to stay involved in Peruvian politics while in Japanese exile, flew to Chile on a private jet. On arrival, he was arrested and Peru demanded his extradition.
Fujimori has been found guilty in four trials since he was extradited from Chile in September 2007.
He was found guilty of abuse of power and sentenced to six years in prison in December 2007.
In July, he pleaded guilty to charges of illegally paying a $15m bonus to Montesinos and was sentenced to seven and a half years in prison. The sentence is under appeal.
And on September 30 he was given another six year sentence and fined $9m after he admitted charges of wiretapping and bribing journalists, politicians and business leaders.