A 36-year-old woman has pleaded guilty to murder for plunging a knife into her boyfriend’s heart at the apartment they shared near the University of Minnesota.

Zara Jo Case admitted Friday in Hennepin County District Court to second-degree murder in the death on Feb. 15 of Joseph “Moochie” McRunnel, 39, at their home in the Como neighborhood.

Case remains jailed without bail ahead of sentencing on June 9.

McRunnel’s parents, neighbors and friends knew him as a “calm, passive person,” while Case was “volatile and confrontational when high or drunk,” the complaint said.

Case told police after the killing that she had recently left substance abuse rehabilitation and was addicted to methamphetamines and alcohol. Her criminal history includes convictions for drunken driving and obstructing police and multiple counts of drinking in public.

The complaint spelled out an increasingly chaotic and violent sequence:

Police were called to the address about 5:25 a.m. by a man in a different apartment who said he barricaded his door to keep Case from breaking in. Officers found Case “extremely intoxicated” and sent her back to her apartment.

Police were called two more times. The last time, police found Case outside and screaming that McRunnel had stabbed himself. Officers found him on his apartment floor.

The Hennepin County Medical Examiner’s Office said the knife went more than 4 inches into his chest and pierced his right ventricle.