Paris (CNN) -- The brother of a gunman killed in a siege in southwestern France was transferred Saturday to the country's counter-intelligence headquarters near Paris for questioning, a police union leader told French TV.
Abdelkader Merah was arrested on Tuesday night as police closed in on his younger brother Mohammed Merah, blamed for shooting dead seven people in three separate attacks.
Mohammed Merah, 23, was killed Thursday at the end of a 32-hour siege of the apartment in the city of Toulouse where he was holed up. He was wanted in the murders of three French paratroopers, a rabbi and three children ages 4, 5, and 7.
A spokeswoman for Paris prosecutor Francois Molins said Saturday Mohammed Merah had been struck more than 20 times by bullets, an autopsy showed.
Most of the impacts were on the arms and legs, Elisabeth Allannic said. There were two deadly wounds on the front left temple and crossing his abdomen, she said.
Police have been questioning Mohammed Merah's mother, brother and his brother's girlfriend, as they seek to determine whether he acted alone in the attacks.
Police union leader Christophe Crepin told French TV news channel i-tele that Abdelkader Merah and his girlfriend were moved early Saturday from Toulouse to the headquarters of the DCRI, the French counter intelligence agency, in Levallois-Perret, near Paris.
Their custody, which was extended Friday, could end as late as Sunday morning under French law.
The brothers' mother, Zoulika Aziri, was released Friday night, police in Toulouse confirmed. She lives in the Toulouse suburb of Mirail, CNN affiliate BFM-TV reported previously.
Police tracked Merah down via his mother's computer IP address, which was apparently used to respond to an ad posted by the first shooting victim, officials said.
The Interior Ministry said Saturday it had lifted the scarlet state of alert, the country's highest security alert level, which was put in place in the Toulouse region following the third shooting on Monday, which targeted a school.
France's prime minister defended the police and intelligence services Friday over their handling of the case, saying they had done well to find Mohammed Merah so quickly
Questions have been raised as to why Merah -- a petty criminal who was placed under surveillance by French authorities after visiting Pakistan and Afghanistan -- was not being more closely watched.
He claimed to have attended an al Qaeda training camp, according to Paris prosecutor Francois Molins, and was on the U.S. no-fly list for that reason, a U.S. intelligence official said.
Fillon told French radio station RTL that "there was no single element" that would have allowed the police to arrest Merah before the killings began.
Toulouse lawyer Eric Mouton, acting for a woman named only as Aicha, to protect her identity, told CNN she filed a complaint against Mohammed Merah in June 2010 over alarming behavior Merah displayed toward her children and herself.
Aicha claimed that Merah had beaten up her daughter, 19 at the time, and had threatened her. He also held her son, 15, against his will in a room for several hours, forcing him to watch extremely violent videos, Mouton said. Merah denied that claim, the lawyer added.
At the time of his death, the case was still open and had not yet gone to trial because of a backlog of cases at the Toulouse public prosecutor's office, Mouton said.
Investigators say Merah filmed the attacks in which he killed seven people.
He was tracked down by police 10 days after the first shooting on March 11.
In that attack, Imad Ibn Ziaten, a paratrooper of North African origin, arranged to meet a man in Toulouse who wanted to buy a scooter Ziaten had advertised online, the interior minister said. The victim said in the ad that he was in the military.
Four days later, two other soldiers were shot dead and another injured by a black-clad man wearing a motorcycle helmet in a shopping center in the city of Montauban, about 50 kilometers (30 miles) from Toulouse.
In the attack at the private Jewish school Ozar Hatorah on Monday, a man wearing a motorcycle helmet and driving a motor scooter pulled up and shot a teacher and three children -- two of them the teacher's young sons -- in the head. The other victim, the daughter of the school's director, was killed in front of her father.
Police said the same guns were used in all three attacks.
CNN's Louis Fraysse, Anna Prichard and Laura Smith-Spark contributed to this report.