It was a cold case until , when familial DNA identified a suspect 39 years after the crime who was charged, tried and convicted of her murder. In , a cold case investigator discovered unidentified blood, presumably belonging to the killer, while he was reviewing case files.
In , a company specializing in DNA phenotyping was hired to produce a new approximation of the killer's appearance based solely off the DNA sample. On August 7, , Burns was sentenced to life in prison without parole. He lived in Manchester at the time of his arrest in and owned a powder coating business in the city. He had worked for John Deere and co-owned a truck stop. Burns had previously been married to Patricia Burns, who died in from suicide.
Her friend declined. Martinko then asked another acquaintance to go to the mall with her; that friend said yes at first but later changed her mind. He began to search for her, as did the police. Martinko had been stabbed 29 times in her face, neck, and chest. Police had few leads and appealed to the public for tips. Police interviewed numerous people, and several were cleared of suspicion through use of a polygraph. A juvenile found carrying a knife was interviewed and ruled out in her murder, as was a shopping center employee who had told police that he enjoyed following women and ogling store mannequins.
Rumors began to circulate about the crime. Some thought that Martinko had received harassing phone calls before her death, but police stated that they did not think so. For some time, a prime suspect in Martinko's murder was a man who had, the month before, broken into a Cedar Rapids home, raped a woman at knifepoint, and threatened to kill her children.
In , while serving a life sentence for an unrelated attack, the man died in prison from colon cancer. Controversy arose five months after the murder, after a woman who was driving by the mall parking lot in the early hours of December 20 came forward with information.
