Judge refuses to release Rihanna's stalker because he could kill her (Pctured)

A judge has said Rihanna is just 'a heartbeat away from tragedy' because of a delusional stalker who may end up killing her if released.

Judge Orlando Marrazzo compared stalker Kevin McGlynn to the man who murdered John Lennon as he denied the homeless man's release from a psychiatric hospital.

According to Mailonline, McGlynn, 54, was arrested last July after hand-delivering letters to the pop star's Manhattan apartment in which he calls her a 'b****' and threatens to 'bum rush' and gang rape her. He also believes he was in a relationship with Rihanna and that she stole his music. Judge Marrazzo says McGlynn 'appears to be a ticking time bomb who is wholly fixated on (Rihanna), and poses a direct threat of serious physical harm or death to her and anyone around her.'

'It is entirely foreseeable that if he were free to continue to act upon his psychotic delusions without this court's intervention, it may result in the death of (Rihanna) or other innocent persons,'

 He went on to call McGlynn 'severely psychotic and delusional' comparing him to Mark David Chapman, the man who shot John Lennon outside the Dakota apartment building in New York, after asking for the Beatle's autograph.