The Crown asked for a stay of proceedings on a separate charge of assault in connection with an incident at Her Majesty's Penitentiary.
Police laid the assault charge after Hart threw a paper plate at prison guards in January 2013. The incident was captured on a security camera.
The Crown described the assault charge as a "distraction" from the more serious threat charge, which occurred during the same incident.
The altercation occurred after Hart, 45, refused to prove to guards that he had swallowed some medication, which is standard protocol at the penitentiary.
Hart was still incarcerated at the time as his legal odyssey continued.
The murder charges were withdrawn against Hart in August 2014 following a Supreme Court of Canada ruling that called into question the reliability of confessions obtained during so-called Mr. Big sting operations.
It was alleged he drowned his two daughters in a lake near Gander in 2002.
He was convicted in 2007 following a lengthy police investigation that included police officers posing as criminal in order to obtain a confession.
Meanwhile, this is not the end of Hart's legal troubles. He is expected back in provincial court later this week on other charges stemming from his behaviour while in custody.
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