A Costa Mesa man who allegedly caused his elderly mother's death by leaving her lying on the bathroom floor pleaded not guilty last week to two felony charges.

Robert Dickerman, 47, told an Orange County Superior Court judge Friday that he was innocent of involuntary manslaughter and inflicting injury on an elder adult, according to court records.

The charges stem from the death of Dickerman's 80-year-old mother, Yoshiko Dickerman.

Police said Dickerman left his mother in a puddle of urine on the bathroom floor for two days before calling paramedics at 2:20 a.m. July 3, 2012.

She died from an infection the next day, police said at the time.

Dickerman, who said he was the sole caretaker of his mother in their cluttered home on Azalea Drive, had also tied her to a bed and portable toilet at times, police said.

Costa Mesa officers arrested him in September.

Dickerman had been held on $1-million bail, according to police, but he was released on bond Monday afternoon, according to jail records.

Dickerman's attorney declined to discuss the case Tuesday.

— Jeremiah Dobruck

Twitter: @jeremiahdobruck