Police say Barbara Sheehan confessed to killing her retired cop husband in their Howard Beach home, saying, "I shot him. I shot him. I think he's dead." Sheehan, charged with second-degree murder, pleaded not guilty and was held without bail. Sheehan allegedly shot her husband Raymond, who retired as a sergeant in the NYPD in 2002 and had been working at UBS in security, Monday morning using two of his guns, a Glock and .38-caliber......