The Supreme Court of Canada has rejected an attempt by a Nova Scotia man convicted of sex crimes to appeal his status as a dangerous offender.

The court gave its ruling in the case of Andrew Paul Johnson on Thursday.

Johnson, who is from Halifax, was arrested in Nanaimo, B.C., in October 1997 after trying to pick up 12-year-old girls while posing as a police officer.

When police caught him, Johnson had a 20-year-old mentally handicapped woman locked in his car.

Two forensic psychiatrists who testified at an earlier hearing into his dangerous offender status said they believed the woman would have been the victim of a violent crime.

At the same hearing, an 18-year-old woman said she believed it was Johnson who molested her in the Halifax public library when she was 11 years old.

Under the Criminal Code, individuals convicted of violent and sexual crimes can be designated as dangerous offenders if it is shown they are at high risk of committing other such offences, and must remain in prison until it's deemed that risk no longer exists.