Vermont police say they have confirmed Rita Curran's murderer using DNA from a cigarette butt and her clothes, over 50 years after her roommate discovered her dead in her room.

Detectives identified William DeRoos, a man who resided in Curran's Burlington apartment complex, as the person responsible for the use of improvements in DNA testing and genetic genealogy, 

The police determined that DeRoos died of a heroin overdose in 1986 in San Francisco. This Vermont murder case has been closed, according to CNN.

On the night of the July 1971 crime, DeRoos, who lived with his wife two floors above Curran, quarreled with his wife and left their apartment to "cool down," per a Burlington police investigation.

A detective stated at the time that 24-year-old Curran was discovered dead after putting up a "vicious struggle" before her death. Authorities are now "unanimously certain" DeRoos was accountable, as the report published Tuesday indicates.

A Case Gone Cold

The following morning, authorities questioned DeRoos and his wife, who maintained they were together all night and did not notice anything.

In 1971, officials looked into the case and gathered evidence in the Vermont murder scene, including a cigarette butt. Burlington Police Detective Lt. James Trieb, commander of the Detective Services Bureau, said it was crucial to solving the Vermont murder case.

Trieb said the object was found near Curran's right arm in 2014 and sent in for Vermont murder DNA testing that same year. Trieb said a male DNA profile was identified, but a check of the country's law enforcement repository for genetic material yielded no matches, NBC News reported.

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Extensive Genetic Research Solves The Mystery

The government partnered with Parabon NanoLabs, a genetic genealogy organization that blends historical study with DNA analysis, to search publicly for indications about the Vermont murder killer's identity.

The company's chief genetic genealogist, CeCe Moore, told reporters Tuesday that she narrowed the list of candidates to DeRoos within a few hours using a publicly accessible database.

Following the finding, officers interrogated DeRoos' then-wife again, who indicated she and DeRoos had fought on July 19, 1971, and he fled.

Trieb noted that after she had gone to bed, DeRoos came back and instructed her to inform the police that they had stayed in their house all night.

Although no charges will be brought, the local state's attorney concluded reasonable cause that DeRoos committed the Vermont murder, according to Burlington Police Department acting chief Jon Murad.

A brother of Curran told reporters that he prays to his parents and his sister, and he does not worry about Rita's murderer, but rather what his sister and their parents went through. according to People.

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