Murder

Answer

Thomas Schneider seems to manipulate results of the experiments. Robert informed him that he would report this to the organization where Thomas is applying for the grant. The amount is $ 3,000,000, which is a serious motive for the murder. He also doesn’t have an alibi, as Maria didn’t see him, but only his clothes. In addition, Thomas was a roommate of Martin’s and he had access to his belongings and could take the syringe. According to all indicators, he is the only one who has no alibi and a serious motive.