Michael Eugene Mullen is accused of killing Nina Fischer in 1973

Using DNA evidence, California authorities were able to arrest a man connected to a murder that remained unsolved for over 50 years.

Michael Eugene Mullen, 75, was arrested for the murder of Nina “Nadine” Fischer, a Swedish citizen who was sexually assaulted and killed in her San Rafael, California, home in November 1973 while her husband was at work during the day, the Marin County Sheriff's Office said.

Fischer's husband, Gunnar, discovered that her naked body bore numerous gunshot wounds, AP and SFGate report. In addition, the victim's hands were bound and her mouth was gagged.

Their 2-year-old child was unharmed in the house. The incident occurred as the couple was planning to return to Sweden. According to reports, the case was not pursued further despite interviewing the removal company and an expert.