According to prosecutors, Merah had told negotiators he went on his rampage to avenge the deaths of Palestinian children and protest the French army's involvement in Afghanistan as well as France's law against the Islamic face veil.
Some politicians, French media and Toulouse residents questioned why authorities didn't stop Merah before he started his killing spree.
Socialist presidential candidate Francois Hollande said questions need to be asked about an "failure" in counterterrorist monitoring. Other candidates did the same, and even French Foreign Minister Alain Juppe said "clarity" was needed on why he wasn't arrested earlier.
French Prime Minister Francois Fillon told RTL radio Friday that authorities "at no moment" suspected Merah would be dangerous despite his long record of crime and his time in prison.
"The fact of belonging to a Salafist (ultraconservative Muslim) organization is not unto itself a crime. We must not mix religious fundamentalism and terrorism, even if naturally we well know the links that unite the two," Fillon said.
In response to the slayings, Fillon said President Nicolas Sarkozy's conservative government is working on new anti-terrorism legislation that would be drafted within two weeks.
Families of the victims expressed frustration that Merah was not taken alive.
"Imad's parents feel that the justice they were expecting was stolen from them," said lawyer Mehana Mouhou, lawyer for the family of the first paratrooper killed, Imad Ibn-Ziaten. "His mother wanted an answer to the question, 'why did he kill my son?'"
Cathy Fontaine, 43, who runs a beauty salon down the street from the building in Toulouse where Merah was killed, said France should have a "zero tolerance" policy for people who seek out training in Afghanistan and perhaps even refuse to let them back in.
"An individual who goes to be trained in Afghanistan, you have to follow him," she said.
The chief of the elite RAID police unit, which conducted the raid, told French media on Friday that he was probably killed by a sniper.
"We tried to exhaust him all night before retaking the apartment," Amaury de Hauteclocque was quoted as saying by Le Monde. His commandos slipped into the apartment but Merah was waiting for them, standing in 30 centimeters (a foot) of water after a pipe burst when it was pierced by a bullet during the first assault, the report said.
"I'd given the order to only fire back with stun grenades. But as he moved through the apartment he tried to kill my men who were on the balcony. It's probably one of the snipers that got him," he said.
He said on RTL radio that 15 men had taken part in the assault, which took about an hour as police slowly penetrated Merah's apartment. He described the apartment like "a battle zone," with furniture piled up as a barricade.
He said if it had been a case of nabbing Merah "dead or alive," the police would have stormed his apartment immediately instead of waiting 32 hours.
"If we have four injured among my men, it's because we tried until the end to get him alive," he said.
Angela Charlton in Paris and Sarah DiLorenzo in Toulouse contributed to this report.
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