Daniel Boustead, 25, attacked the off-duty officer on a York-bound train as she was sat chatting with a friend.
Aisha Wadoodi, prosecuting at York Crown Court, said that Boustead, who has serious facial disfigurements, got on the train at Bradford and sat in front of the two women. He kept staring at the victim and touched her sexually after reaching through a gap in the seats.
“He was asking her what her name was,” said Mrs Wadoodi. “She was shouting for him to stop and pushing him away.”
Bizarrely, Boustead began writing furiously in a notepad, apparently jotting things down to say to the woman. After his arrest, he told police he was attracted to the victim and just wanted to get her attention.
Boustead admitted sexually assaulting the victim - who was not known to the defendant - on June 3 last year.
He also admitted sexually assaulting a healthcare assistant about four months later, when he made a “disgusting” remark to her before pulling her T-shirt up to expose her bra.
“The victim said he was smiling while this happened and she felt scared,” said Mrs Wadoodi.
During police questioning, Boustead tried to make light of the attacks and kept making disturbing comments about his warped sexual fantasises and obsessions regarding “women and corpses”.
Mrs Wadoodi said Boustead had previous convictions for harassing women which had led to prison sentences in the past. He had a reputation for stalking “particular types” of women in the street and threatening to carry out serious sexual assaults on them.
His barrister Chris Dunne said Boustead clearly had psychological problems, adding: “His behaviour is worrying and he accepts that.”
Boustead - formerly of Castle Road but currently of no fixed abode - appeared for sentence after being remanded in custody.
Judge David Batty QC described his behaviour towards women as “extremely troubling” and said the attack on the nurse was particularly “humiliating and unforgiveable”.
Mr Batty had toyed with the idea of imposing a hospital order to better protect the public, but because psychological reports had not provided a clear diagnosis regarding Boustead’s condition, he said appropriate treatment would be difficult.
Instead, Boustead was given an eight-month prison sentence, suspended for two years, during which he will be monitored by the Probation Service and take part in a rehabilitation programme.
Mr Batty also imposed a four-month curfew which will keep Boustead indoors between 9pm and 7am daily. That order was held in abeyance until Boustead can find new accommodation.
He was also put on the sex-offenders’ register for 10 years and subjected to a sexual-harm prevention order, to run indefinitely, which bans him from having any contact with the victims. The order also prohibits him living or staying in any household with a female under 16 years of age, or having any avoidable contact with under-age girls.