CNN is trying to prop up one of Bill Cosby ‘s key accusers with unethical, malicious tactics … so claims Cosby’s lawyer. Marty Singer has written a scathing letter to CNN Prez Jeff Zucker , claiming his reporters are out to get Cosby in a special the network is doing with model/actress Beverly Johnson . Singer says in his letter — obtained by TMZ — he contacted the CNN reporters and told them they should get in touch with Mark Burk , who was Johnson’s live-in boyfriend from 2006-2009. Singer says Burk told CNN reporters Beverly “never said a negative statement about Bill Cosby throughout their entire four year relationship.”