DAVIE, FLA. (WSVN) - After nearly four decades, the Davie Police Department said they have solved the 1987 murder of 28-year-old Marilyn Decker, identifying the suspect through advanced DNA analysis and genetic genealogy.
At a news conference on Thursday, detectives touted the law enforcement effort behind solving this case.
“We have solved the cold case after 38 years of intensive investigation,” said Davie Police Chief Steve Kinsey.
Decker’s body was found floating in a canal near the 3000 block of Flamingo Road on Oct. 3, 1987, with multiple stab wounds.
The Broward County Medical Examiner’s Office ruled her death a homicide caused by asphyxiation. Despite multiple suspects and years of investigation, the case went cold in the 1990s.
In 2021, Davie Police’s Cold Case Unit reopened the investigation, reexamined evidence, and partnered with the Florida Department of Law Enforcement, Astrea Forensics in California, and Parabon NanoLabs.
That year, they placed billboards across the county asking for information.
However, detectives said using DNA extracted from hairs recovered from the scene, Chief Genealogist CeCe Moore built a genetic tree that led investigators to a suspect — Donald Lawless, born in 1925 in Ohio.
“We continued investigating and contacted experts to process DNA of hairs left behind on Marilyn Decker. A genetic tree was provided to us with a possible suspect. After lots of work, we had success and a suspect was identified,” said Kinsey.
Police said they determined Lawless lived in Florida, including in Davie, during the 1980s and had an extensive criminal history dating back to the 1940s.
Although he died and was cremated in 1995, investigators obtained DNA from a close relative and confirmed Lawless as the man responsible for Decker’s death, police said.
“Like you guys know, there’s a lot of technology that has changed and that has helped us in so many ways,” said Davie Police Detective Eddy Velazquez.
The Broward County State Attorney’s Office reviewed the case and agreed there was sufficient evidence to charge Lawless, officially closing the case after 38 years.
Detectives provided a younger picture of the suspect, who was in his 60s at the time of the murder.
Davie Police said they have remained in contact with Decker’s family, who have been informed that justice has finally been served.
The victim’s sister was present at Thursday’s news conference. She said their mother rarely spoke about the murder when she was alive, but always wanted to know who was responsible for the 28-year-old’s death.
“She kept saying, ‘I wish I found out who killed your sister. It’s not right what they did. They took her away from us and I wish I knew,'” said the sister.
She added she wishes Lawless would’ve paid for his crimes.
Police say Lawless may have been involved or responsible for other similar crimes across the country. They say an investigation into that possibility remains ongoing.
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