[url]http://stacks.msnbc.com/news/819026.asp[/url]

  A decade ago, a shotgun-wielding assailant terrorized two Northwest Washington neighborhoods with a series of attacks. The attacker, dubbed the shotgun stalker by police and residents, shot at 14 people in Columbia Heights and Mount Pleasant.
      Once they concluded that a serial shooter was on the loose, D.C. police saturated the affected neighborhoods with round-the-clock foot and car patrols. But their presence did not stop the attacks.
      Police who investigated that case say it is virtually impossible to catch a serial shooter in the act. “Prevention is something you have to do, but it’s not how you stop it. Apprehension is how you stop it,” said J.T. McCann, a former D.C. homicide detective and supervisor who now works as a private investigator. “There are thousands of people on the street. There are thousands of street corners.”  
   McCann said they tried to cast as wide a net as possible when searching for the shotgun stalker, researching sales of shotguns and ammunition, running down leads of vehicles that fit one witness’s description and searching for connections among the victims or locations that might show why they were targeted.
      The assailant was caught after he changed his pattern: Instead of shooting at night, he got brazen and fired during the day, allowing a witness to get a partial license plate number. The gunman’s car eventually was spotted by an off-duty officer who saw it going through red lights.