DWI Leads to Mo. Man's Arrest in Cold Case Killing A Missouri man forced to provide a DNA sample after pleading guilty in a drunken driving case has been charged in a 23-year-old killing. Prosecutors announced Friday that Guy Shannon Jr., 43, of Odessa, faces charges of first-degree murder and forcible rape. Shannon is accused of strangling and assaulting Marcia Lynn Davis, 20, of Independence, in March 1989. Davis was last seen leaving the Jackson County Jail after visiting a friend. A homeless person found her partially clad body in an abandoned apartment building the next day, according to a probable cause statement filed in the case. Shannon became a suspect after he was convicted of driving while intoxicated in 2010 and, as a felon, had to give a DNA sample. It was entered in a database and ultimately linked him to genetic material found on Davis' body. Authorities said only one in 10 quadrillion unrelated people would have the same genetic profile. Davis' friends and family were shown Shannon's photo but didn't recognize him, the probable cause statement said. When interviewed, Shannon said he had never seen Davis before. He told authorities he had never been to the building where her body was found or picked up hitchhikers or women on the street. Shannon requested an attorney when told his DNA was found on the victim, the probable cause statement said. Although the charges were filed Monday, the case was temporarily sealed until Thursday, when the warrant was served. Bond has been set at $350,000. No attorney is listed for Shannon in online court records. In the early 1970s, Kansas City police started more carefully archiving physical evidence from hundreds of unsolved homicides, rapes and other crimes, often storing it in a giant freezer in the city's crime lab. Ensuing technological advances made the practice pay off, with numerous cold cases solved with the old physical evidence. One of the most newsworthy arrests was of Lorenzo Gilyard, a former trash company supervisor initially charged with killing 13 women. In 2007, he was convicted of six of the killings.