Lawyers for the family of a slain Democratic Republic of Congo activist have filed a complaint against Kinshasa's police chief and associates for their suspected role in the killing, one of the advocates said on Friday.Activist Rossy Mukendi was shot dead in February in a rally in the capital against President Joseph Kabila, which was organised by a group close to the Catholic Church before key elections next month."I have filed a complaint with the military prosecutors office against General Sylvano Kasongo and his associates for acting as a criminal organisation in the assassination," lawyer Richard Bondo told AFP.He said the complaint accuses the general in the theft of the murder weapon and being suspected of "substituting" the author of the crime with another innocent police official."We are not aware of any complaint, if there is a complaint, then they will send it to us," police spokesperson Colonel Pierrot-Rombaut Mwanamputu, told AFP. He is also named in the complaint.Part of the "Collective 2016" movement, the activist was shot dead on February 25 in a security force crackdown on the opposition march in Kinshasa to demand an end to Kabila's time in office.In power for nearly two decades, Kabila has since ceded to international pressure to step aside and he will not run in December's delayed presidential election.Police said after the death of Mukendi that they had used rubber bullets to break up the protest.A police officer was put on trial for the activist's death a week after he was buried. But the trial was suspended in May. No date has been set for a restart, Bondo said.The lawyer claimed the police officer detained was not the real suspect in the killing. He did not explain why or give any proof, but named another police official who he said should be on trial.Twenty-one candidates are running in a December 23 election closely watched by Western governments as the vast African nation attempts its first peaceful transition of power since the end of Belgian colonial rule in 1960.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.