If there are people covering for suspect who do not come forward on their own there are at least two possibilities, and probably more. 1.) They could, at some point, be considered an accessory to a crime. 2.) If there was enough circumstantial to charge a suspect and bring him to trial, they could be considered hostile witnesses. Both of these options are very, very serious. If someone is covering for the suspect they need to be considering this. Are they willing to lose their entire vocation, the support of the community and possibly go to jail for the suspect? If they come forward, they will likely gain some amount of respect and compassion from others, not to mention fewer legal consequences.