Stabber of tourist mom in Macy’s said she ‘wanted to go to prison’ rather than back to mental hospital

The unhinged woman charged with stabbing a tourist changing her baby’s diaper at Macy’s Herald Square brazenly admitted that she “wanted to go to prison” — rather than back to a mental hospital, prosecutors said Wednesday.

Kerri Aherne, 43, made the stunning confession to cops shortly after she was arrested for allegedly randomly attacking a 39-year-old California mom inside the iconic Midtown store on Dec. 12, a court heard.

“(She) said she couldn’t tolerate hospitals any longer and wanted to go to prison rather than be returned to a hospital,” Assistant District Attorney Paul Barker revealed at Aherne’s Manhattan Supreme Court arraignment.

Aherne, wearing a pink sweatshirt over grey pants, pleaded not guilty to attempted murder, assault and endangering the welfare of a child charges in front of Judge Ann Thompson.

The homeless former home health aide from Massachusetts took a cab from her transitional housing unit at the Manhattan Psychiatric Center to the famed department store, she told The Post in a jailhouse interview.

Prosecutors said Aherne purchased a large kitchen knife from Macy’s before heading to the seventh floor bathrooms around 3:10 p.m., where she stabbed the unsuspecting woman in the back as the new mom was changing her 10-month-old daughter.

“(She) looked for someone to kill because voices in her head told her that she had to kill someone or else she would be killed,” Barker told the court.

The judge ordered Ahearn remanded to jail and for her to undergo a psych evaluation before her next court appearance Feb. 11.

Aherne had previously been hospitalized for a year of treatment for mental health issues, prosecutors have said.

She faces up to 25 years in prison if convicted of the top count.