A man who raped a woman while she was on a video call to her boyfriend was caught with the help of a screenshot he took of the attack.
Samuel Fortes followed the woman through Leeds city centre before raping and repeatedly punching her last June.
The 20-year-old was on a FaceTime call at the time and the screenshot formed a "key piece of evidence", West Yorkshire Police said.
Fortes was jailed for life and must serve a minimum term of eight years.
The woman, who was 19 at the time, was left with extensive facial and dental injuries, as well as cuts and bruises.
Fortes, 27, of Ironside Road, Sheffield, followed her to an isolated area before attacking her under a flyover footbridge adjacent to Grace Street in the 15-minute ordeal at 03:15 BST on 23 June, the Crown Prosecution Service said.
In a victim impact statement read to the court, she said "I thought I was going to die".
"It is a feeling that no words could ever describe.
"I have experienced what I hope to be the lowest point, mentally, in my life.
"There were days, at the beginning of my recovery period, where I could not leave my bed and that is simply because I did not see a point in doing so."
Det Supt Jaz Khan said the screenshot from her boyfriend's FaceTime app was "a key piece of evidence", along with DNA and CCTV footage, which helped catch the "highly dangerous sex offender".
"Fortes subjected this brave woman to a horrific ordeal and I want to praise her for her bravery in helping to bring her brutal attacker to justice," he said.
Fortes admitted rape and and grievous bodily harm and was sentenced at Leeds Crown Court. He was also placed on the sex offenders register indefinitely.