An Egyptian court has sentenced a policeman to three years in prison and another to six months over the killing of a detainee in custody, relatively light sentences that prompted a backlash on social media.The Cairo Criminal Court convicted the two of beating Mohamed Abdel-Hakim to death in a police station in Cairo's Mokattam neighbourhood in January. But it said he was killed by mistake during an interrogation and did not charge the policemen with torture.The verdict, which was announced on Sunday, can be appealed.The killing outraged area residents, who set a police car ablaze, hurled stones and tried to storm the police station. Police arrested 43 protesters who face an array of accusations that include damaging public property and taking part in illegal protests.Egypt banned all unauthorised protests in 2013 as part of a sweeping crackdown on dissent.Abdel-Hakim's lawyer, Mayada Mtawea, told local media she was surprised by the leniency shown by the court, a view that was echoed by many on social media.Anger at widespread police brutality helped spark the 2011 uprising that toppled longtime autocrat Hosni Mubarak. Rights groups say mistreatment and torture are still widespread in Egyptian detention facilities. Authorities deny any systematic abuse and say those found guilty of mistreating prisoners are held accountable.Egypt has jailed tens of thousands of people, including several prominent activists behind the 2011 uprising, since the military overthrew an elected but divisive Islamist president in 2013. Many have been held for months or even years without trial.Police had initially claimed that Abdel-Hakim died of a drug overdose, but a forensics investigation later confirmed he was beaten to death.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.