THEY started arriving six years ago. Notes, scrawled inside greeting cards, from a stranger called "Gordon".
The messages, always written in caps and always signed with five kisses (one large cross with four small crosses around it) were unsettling from the beginning.
The cards often featured an animal on the front, usually a cat, and the cuteness of the design jarred with the odd words inside.
But two years ago the notes, sent to a woman in her 40s in Bristol, England, took on a more sinister tone as the author morphed from secret admirer to dangerous stalker, signing off as "your rapist".
Fearing she could be attacked at any moment as the stranger promised, the woman walked into a police station in January 2016 and told them her story.
Yesterday, investigators from Avon and Somerset Police took the unusual step of releasing photographs of some of the cards in the hope somebody will recognise the handwriting.
"The content is becoming increasingly sexually explicit and aggressive in nature and includes threats to rape and stalking offences," Detective Constable Patrick Prescott said in a video addressed to the public and posted on social media.
Detective Prescott said his team had been working with a criminal profiler from Britain's National Crime Agency to analyse the correspondence and "risk-assess the offender's behaviour".
He said it was possible Gordon had sent letters to other people and urged anyone who had received similar cards to contact police.
"Thorough analysis of the communications has been carried out and the possibility the offender has sent, or is sending cards or letters with similar content to other people cannot be excluded," Detective Prescott said.
"If you have been receiving similar correspondence then we want to hear from you.
"You may recognise one or more of the characteristics but can't believe the person you have in mind would commit offences like this. It could be a colleague, friend or even a family member.
"We'd ask you to please report any concerns or suspicions to help us make this stop.
"Harassment offences can cause significant distress to victims and disrupt their daily lives but we'll do all we can to make sure we investigate crimes, gather evidence and whenever possible, bring offenders to justice."
Detective Prescott said the cards had all been sent from within the Bristol postmark area to the woman's Bristol address. The victim, whose name is being withheld for her own protection, issued a written statement via police.
"This has been going on for so long - someone out there must know who it is," she said.
"Whether it's the distinctive crosses, the handwriting or the name they call themselves, if you recognise anything that could help the police, please let them know."
Detective Prescott also appealed to stationary shop workers and postal workers who may have unwittingly come into contact with the stalker.
"If you work in a shop which sells cards, or if you work in the postal service, do you recognise the handwriting or the distinctive pattern of crosses?" he said.
Investigations are continuing.
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