BECKLEY, W.Va. -- Drug cases going back 15 months are being dismissed because the evidence is missing from the Beckley Police Department's property room, Raleigh County officials said Wednesday. Prosecuting Attorney Kristen Keller told The Register-Herald that police notified her of the missing evidence and the first case was dismissed Wednesday. Evidence rooms serve as holding facilities for items such as money, drugs and guns obtained during investigations. Keller explained that once evidence control is compromised, the prosecutor's office has no choice but to dismiss the charges. Previous convictions or guilty pleas also could potentially be vacated if a person or his or her attorney believes that the chain of custody for the evidence in their case was compromised. "The first disclosure came to us on Friday and we've been dealing with trying to find out exactly what the scope of the problem is,'' Keller said. "I'm estimating scores, maybe a couple hundred cases.''Cases in which drugs were placed at the sheriff's department or the West Virginia State Police will not be affected, Keller said. During a Wednesday news conference, Beckley Police Chief Tim Deems said that Gabriella Brown is the department's technician responsible for the department's evidence room. She went on medical leave late last week. Deems also said that he notified U.S. Attorney R. Booth Goodwin's office about the matter Wednesday morning. Deems told the newspaper Tuesday that an internal inventory of the department's evidence holding room was under way. Officials said an inventory of evidence for all cases is ongoing. Keller said that the public should be gratified that the police department immediately let her know about the problem. "The fact of the matter is, if they wanted to, they absolutely could have covered this up and no one would have ever known,'' she said. "They really are to be commended for immediately making the necessary disclosures and taking the actions to address the problem.''While all attorneys will be notified of the situation, Keller also is urging anyone who has pleaded guilty or who has a pending case to consult with an attorney or contact the prosecutor's office to see if their case may be affected.