However, Mohamed Merah's older brother and his girlfriend remain in custody in Paris. The couple was transferred to anti-terrorist headquarters on Saturday. Police say there is evidence to suggest that his brother worked as an assistant.
Authorities say Merah filmed himself carrying out the attacks, which began March 11. Three Jewish schoolchildren were killed as well as a rabbi and three French paratroopers.
Merah later died in a stand-off with police.
Investigators are trying to figure out whether the 23-year-old acted alone. Merah, a Frenchman of Algerian descent, claimed allegiance to al Qaeda, but so far it's unknown whether there is a connection.
The Associated Press contributed to this report.