Benjamin Halsey pleaded guilty at Hornsby Local Court on Tuesday to three counts of sexually touching without consent, stalking or intimidation, resisting a police officer, and possessing suspected stolen goods, in relation to four separate incidents on Sydney trains and railway stations.

About 11am Monday, a 17-year-old girl was leaving a train at Central station when 26-year-old Halsey sexually touched her.

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She reported the incident to railway staff, who contacted police.

Halsey then boarded a Newcastle-bound train and approached a 21-year-old old woman, making her feel uncomfortable.

He left the train at Epping station and the woman reported the incident to police at Gosford.

About noon, a 17-year-old girl was leaving the toilets at Macquarie University Metro railway station when Halsey pushed her back inside.

The girl pushed him away, and later that day told police about the incident.

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Then at 12.30pm, another 17-year-old girl was leaving the toilets at the same station when Halsey dragged her back inside. But the girl got away and contacted police.

Police officers from the Ryde police area command attended the station and arrested Halsey on the platform.

At the same time, Police Transport Command officers were monitoring CCTV and liaising with each other in relation to the earlier incidents, and established a link between the four events.

Halsey remains in custody and will return to Hornsby Local Court for sentencing later this month.

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