Chilling update in horrific murder of teen girl found dead five decades ago - as her sister pens heartbreaking letter pleading with new suspect to confess

The sister of a teenage girl who vanished in the 1970s has spoken about her extraordinary life-long quest for answers - culminating in her penning a letter to a notorious American serial killer this year. 

Maryann Collette was just nine years old when her sister, Patricia Newsom, 16, went missing from her boarding school in the Monticello area of New York.

Patricia's whereabouts had remained a mystery until last year, when Maryann's DNA was used to identify her as the victim in a cold case murder from August 1975. 

An unknown suspect had suffocated, gagged and wrapped the teen in tarpaulin before leaving her body in New Haven, Connecticut - but the case had been deemed a 'Jane Doe' mystery which baffled detectives for decades. 

Fast-forward to 2024, and her little sister, Maryann, now 59, lives a peaceful life in Blountville, north-east Tennessee, where she keeps chickens that could be heard clucking in background of her call with DailyMail.com - belying the dark story she was about to unpack. 

Maryann Collette was just nine years old when her sister, Patricia Newsom (pictured), 16, went missing from her boarding school in the Monticello area of New York

Maryann, now 59, lives a peaceful life in Blountville, north-east Tennessee , where she keeps chickens that could be heard clucking in background of her call with DailyMail.com - belying the dark story she was about to unpack

Maryann explained to DailyMail.com why she wrote to the man she thinks is responsible for her sister's death - notorious 'Times Square Killer' Richard Cottingham (pictured)

Maryann described her painstaking search for answers about what happened to her beloved sister - while explaining why she wrote to the man she thinks is responsible - notorious 'Times Square Killer' Richard Cottingham. 

'Writing to a serial killer is not something I saw coming up on my cards,' Maryann told Dailymail.com. 'But I was looking for my sister for 47 years. If I got a confession, it would mean I was done with that chapter of my life.' 

'You have to take your emotion out of the situation,' she added. 'I'm a very direct person. He's alive. I wanted to know, did he kill my sister? Does he remember anything about my sister?

'Because he's old and I don't know how much he will remember, I basically explained to him a little bit about who my sister was, why I was writing to him, and why I thought he may have been responsible.'

Patricia's body was found on August 16, 1975, in a drainage ditch in New Haven, Connecticut. At the time, detectives new only that she had died by asphyxiation, and the case would remain unsolved for decades.

Maryann said she believes Cottingham, also known as the 'Torso Killer' is the killer because of similarities between how Patricia was found and several other of the murderer's victims. 

'There are some similarities with some of his other crimes: the way the bodies were left, the manner of murder - and the things he didn't do to them,' she told DailyMail.com.  

'I have been able to rule out so many other serial killers. I can't rule him out.'

Maryann Collette was just nine years old when her sister, Patricia Newsom , 16, went missing from her boarding school in the Monticello area of New York. (Pictured: Maryann, left, with her sister Patricia, center, and their late brother Peter, right

Patricia's body was found on August 16, 1975, in a drainage ditch in New Haven, Connecticut. At the time, detectives new only that she had died by asphyxiation, and the case would remain unsolved for decades

Patricia's identification came in April last year after Maryann shared her DNA from genealogy company Ancestry with a publicly available database called GEDmatch, which compares data samples from different testing companies

Cottingham, 77, claims to have killed as many as 100 women across Florida, Connecticut, New York, Pennsylvania, New Jersey and Baltimore in the latter half of the 20th century. 

Although he was notorious for mutilating the corpses of some victims, which was not the case with Patricia, many of his murders also involved leaving the bodies untouched. 

'I found an old interview with him,' Maryann said. 'He talked about putting some young ladies down a well after he killed them, and it worried him that they would be decomposing.'

She drew parallels between this self-proclaimed concern of Cottingham's, and the fact that Patricia's body was left in a place it would easily be discovered. 

Patricia's identification came in April last year after Maryann shared her DNA from genealogy company Ancestry with a publicly available database called GEDmatch, which compares data samples from different testing companies. 

When asked what this moment was like, Maryann said: 'Unbelievable. It's still unbelievable. Forty-seven years, that's a really long time.

Patricia has now been laid to rest beside their mother and grandparents in their family cemetery in Pennsylvania

'A detective from our local police department came down to my house and asked if I might have a word with him. He got me on a call with the captains, and they said, "We found your sister." I mean, what do you say to that? 

'There's a piece of me that's been missing my whole life and now I have that missing piece.'

Maryann noted that she was wearing a pendant necklace containing Patricia's ashes. 'She's always with me,' she said. 

Patricia has now been laid to rest beside their mother and grandparents in their family cemetery in Pennsylvania. 

Maryann said she doesn't know whether Cottingham has yet received her letter - or whether he will write back. 

However, East Haven Police Captain Murgo, who was the one who notified Maryann of Patricia's identification, said he has been trying to set up a meeting with Cottingham to discuss the case. 

'Mr. Cottingham was active in the mid to late 60s all the way up to the time he was apprehended in New York City in 1980 so that definitely fits the timeframe in which Patricia was killed,' he told NBC News.