12:47 PM PT -- TMZ's obtained the court docs in which Cassie claims Colton's been stalking and harassing her with unsettling text messages. She claims Colton also went as far as planting a tracking device taped to the bottom of the back bumper of her car to keep track of her whereabouts.
And, then there's this ... Cassie claims Colton's been showing up uninvited to her L.A. apartment and parent's house in Huntington Beach. She claims he takes obsessive walks to her apartment complex and loitered in the alley outside her bedroom window at her parent's Huntington Beach house at 2 AM.
Cassie -- who says they broke up in mid-April -- goes on to claim some of the harassing text messages included accusing her of hanging out with her old ex-boyfriend. She alleges Colton also sent anonymous text messages to her and to himself pretending to also be a victim of the anonymous stalker. Cassie claims Colton later admitted to sending the messages and planting the tracking device.
According to legal docs, obtained by TMZ, Cassie filed Friday in Los Angeles. It's currently unclear what her allegations are against him and if a judge has signed off on the order.
Colton picked Cassie at the end of his season of "The Bachelor" in 2019 ... but the two never got engaged. The couple announced their split in May of this year, and there were rumors that the breakup was a bad one ... but it was unclear what exactly happened.
Colton also had some health issues just before the split ... as he tested positive for COVID-19.
We've reached out to Colton's rep ... so far no word back.