Piecing Together Decades-Old Murder Cases, Increasing Because of DNA Evidence, Is a Challenge Evan Lewis/Texarkana Gazette Delma Banks Jr. is on trial again for the 1980 murder of Richard Whitehead, 16, whose parents are in the front row. Mark Norwood will be led into a Georgetown courtroom Wednesday to face capital murder charges for a killing that took place more than 25 years ago. If Mr. Norwood, 57, goes to trial in the 1986 beating death of Christine Morton, prosecutors and defense lawyers will have to piece together a decades-old crime. That was what lawyers did for the trial of Dennis Davis last year, when he was convicted of the 1985 murder of his former girlfriend. With the advent of DNA science and other technological advancements, it is no longer unusual for juries to see evidence from crimes that happened as long ago as the 1970s. But old cases present unique challenges for prosecutors and defense lawyers: Key witnesses may have moved or died, documents could have disappeared, and evidence collection standards are now much stricter. "The farther back in time you're talking about, the more those things fray and disintegrate," said Rob Owen, a University of Texas School of Law professor who specializes in death penalty cases. Mr. Norwood was arrested in November for the Aug. 13, 1986 murder of Mrs. Morton. Michael Morton, Mrs. Morton's husband, was convicted of her murder in 1987 and spent 25 years in prison. But he was cleared last year after DNA testing was performed on a bandanna found about 100 yards from the Mortons" North Austin home, where she had been beaten to death in bed. Tests showed the biological material on the bandanna was not Mr. Morton's, and a national database search revealed the DNA matched Mr. Norwood's. His DNA was also linked to a similar Austin murder that happened on Jan. 13, 1988. Like Mrs. Morton, Debra Masters Baker was beaten to death in her bed, and Mr. Norwood is a suspect in that cold case. Russell Hunt Jr., Mr. Norwood's lawyer, expects the judge to delay this week's hearing to allow him and state prosecutors more time to investigate. People change over time. People's memories change over time," Mr. Hunt said, adding, "Physical evidence gets moved. Physical evidence is stored in different ways. Mr. Hunt said that verifying other information and determining its relevance to Mr. Norwood could be a challenge. For example, other evidence that recently came to light in the Morton case includes a check cashed after Mrs. Morton's death with her forged signature and a report that her credit card was fraudulently used days after her death. "We don't know if it's possible to go back and find people involved or records involved," he said. Things get lost, and people get lost. When Mr. Davis was convicted last year of murdering his former girlfriend, he was represented by Wade Russell, an Austin lawyer. "There's just myriad problems" mounting a defense in a two-decades-old case, Mr. Russell said. Natalie Antonetti was beaten in the head while she slept on her couch on Oct. 13, 1985. The case was cold until 2006, when Mr. Davis's estranged wife told the police her husband had said that he had "sinned against God and man." She later reconciled with Mr. Davis, and refused to cooperate with police. But investigators reopened the case and focused on Mr. Davis. The woman Mr. Davis told police he was with the night of the murder told investigators who reopened the case that she did not have an entry in her journal noting that she was with him when the police called, and it was something she would have recorded. A quarter-century after the murder, Mr. Russell began digging through the old police file to investigate his client's case. The original police investigator had died. The police case file was incomplete and unorganized, he said. "I would find handwritten notes from various people," he said. You have a lot of sketchy information, and you don't know how it fits into the picture.