French prosecutors have appealed against the sentences against a man and a woman accused of aiding their brother’s shooting spree in which he killed a rabbi and three children.

Abdelkader Merah was jailed for 20 years and his sister Fettah Malki received a 15-year sentence last Thursday after the Special Criminal Court in Paris found them guilty of terrorist offences. 

But public prosecutor Naima Rudloff is understood to have been disappointed by the sentences, after seeking the maximum penalty of life imprisonment for the pair. 

Merah and Malki’s brother, Mohamed Merah, killed seven people — including three Jewish children shot at point-blank range — and maimed six others in the southern French towns of Montauban and Toulouse between March 11 and March 19, 2012. He was killed by security forces three days later.

The verdict provoked a string of criticism from French civil society. 

Moroccan-born Latifa Ibn Ziaten, 57 — whose son Imad Ibn Ziaten was one of Mohamed Merah’s victims — said that her son had “died in vain since the court did not go far enough” against the gunman’s accomplices. Imad was an off-duty sergeant in the First Paratroopers Regiment, an elite unit in the French army, when he was killed. 

Ms Ibn Ziaten has since become an activist for interfaith peace in opposition to against radical Islam.

“People in France are too naïve” in these matters, she said.

“Islamist terrorists may understand the verdict as a sign of weakness,” was the Representative Council of French Jewry’s response, while the conservative mayor of Toulouse, Jean-Luc Moudenc, said the “minimal-level condemnation” meant he could only think of the victims. 

Ms Rudloff, a prosecutor in the Paris Criminal Court for 27 years, is a known critic of the French judicial system and, two years ago, founded Jurispensées, a think-tank for judiciary reform. 

She argued that the court hearing the Merah-Malki case “did not draw all the judicial consequences of the facts”. 

According to Elie Korchia, one of the Jewish victims’ main counsels, Ms Rudloff has an “encyclopaedic vision of the case”. 

The prosecution case is said to have comprised of 117 volumes of several hundred pages each. Coupled with her wariness of the judicial system’s shortcomings, Ms Rudloff is expected to use the case as an opportunity to advance her views on the French legal system.

Abdelkader Merah’s defence counsel was Eric Dupont-Moretti, a lawyer routinely dubbed in the French media as “the Acquitter” for his impressive record even in seemingly desperate cases.

He insisted throughout the trial that the court should stick to the letter of the law and not allow public opinion to interfere with the due process of justice — remarks that may have influenced the court in some measure.

But the trial has been an eye-opener for many, giving French public opinion a better picture of what jihadist-inspired terrorism looks like in their own country.

Many were shocked by the defendants’ staunch identification with radical Islam and their lack of compassion for Mohamed Merah’s victims. 

And many realised for the first time, that French Muslim soldiers were as brutally targeted as Jews.