Shooting erupted in the kosher grocery store at Porte de Vincennes, eastern Paris, on Friday afternoon with reports of six people taken hostage.
"It is the Montrouge shooter," a police source said, referring to Thursday's killing of a female police officer just outside the capital.
Police on Friday said that a link had been established between the Montrouge suspect and Chérif and Saïd Kouachi.
They knew each other, according to France 2 TV, while weekly Le Point said that they belonged to the same jihadist network, which was sending would-be fighters to Iraq, leading to Chérif Kouachi's imprisonment in 2005.
"The suspect has been identified. Two people very close to him have been taken into custody," a police source said.
On Friday afternoon police issued a wanted notice for a woman and a man - Hayat Boumeddiene, 26, and Amedy Coulibaly, 32 - in connection with the Paris violence.
Both were likely to be armed and dangerous, they warned.