California investigators cracked a 51-year-old rape and murder last week after DNA led them to a suspect in Idaho.

Michael Eugene Mullen, 75, was arrested in Lemhi County on Wednesday and charged with the death of Nina “Nadine” Fischer in November 1973.

Fischer, 31, lived with her husband and their toddler daughter in unincorporated San Rafael, according to the Marin County Sheriff’s Office. Her husband found her body when he returned home from work.

According to ABC News, the Fischers were both Swedish nationals and were preparing to move back to Sweden at the time of the murder. Nina Fischer was shot three times. Her 2-year-old daughter was not physically harmed and was found in another room.

Investigators worked the case, but it went cold with a lack of leads, the sheriff’s office said.

The sheriff’s office sent the case to the state Department of Justice’s Familial Search Program in 2021 for help in finding a DNA lead, and after several months, the program came back with one.

“An in-depth investigation was conducted over the next three years to confirm the investigative lead and the suspect was identified as Michael Eugene Mullen, a resident of Idaho,” the sheriff’s office said.

Mullen was arrested and booked into the Lemhi County Jail pending extradition to California.

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[Featured image: Michael Eugene Mullen/Lemhi County Jail]