Right now police are still waiting to re-interview the fiance of a pregnant woman that was killed in November. Police are now calling the fiance a suspect. Police want to know where Keyon Pittman was the night his fiancee was killed. So far he has not given them an alibi.   A detective working the case says they have been waiting on some key evidence, but they have not been able to get the evidence because there is a back log at the state crime lab. Tonight at 5, we are working to find out what is causing the delays at the crime lab, not just in this case but others cases also.  Tune in to News Channel 12 at 5 for the story.