Credit: Courtesy of Cumberland County Jail, via WGME

A Portland man pleaded guilty to the strangling death of his girlfriend.

Gregory Vance, 62, murdered Patricia Grassi in an apartment on Cumberland Avenue in March.

Police found Grassi’s body during a well-being check.

Vance said he strangled Grassi because she was “tormenting” and “slapping” him, according to court documents. He also confessed in phone calls to his daughter and ex-wife.

He originally pleaded not guilty in May. Vance will be sentenced in December.