A psychologist who evaluated a Highland Park woman accused of stabbing her son's ex-girlfriend to death and holding her grandson hostage during a four-hour standoff with police does not believe she was insane at the time of the crime.

Margo Gilbert said she evaluated Onita Higdon at the Center for Forensic Psychology in Saline to determine whether she was responsible for her actions at the time of the crime.

Higdon, 55, is on trial for first-degree murder in connection with the death of 26-year-old Milah Perry on July 12, 2010. Higdon, who suffers from mental illness, has pleaded not guilty by reason of insanity.

"It is my opinion that she met the criteria for mental illness," Gilbert said of Higdon, "but that she did not meet the criteria for legal insanity."

Police said Perry and her ex-boyfriend, who is Higdon's son, left Higdon's home on Candler Street in Highland Park shortly before noon, but Perry realized she had left her purse in the house.

When Perry returned to get her purse, investigators said, Higdon attacked Perry and took her 3-year-old son -- Higdon's grandson -- hostage, resulting in a police standoff.

An autopsy revealed Perry had been stabbed multiple times by what appeared to be a kitchen knife.

Gilbert said she met with Higdon four times at the forensic center before issuing a report to the court about her opinions.

During their first visit in February 2011, Gilbert said she spoke to Higdon for 20 minutes and that Higdon was reluctant to talk about the crime.

"I thought she was paranoid by the ways she interpreted people in prison," Gilbert said. "She thought people were intentionally slamming doors to irritate her."

By the fourth visit in October 2011, Gilbert and Higdon spoke for more than two hours. Higdon said she was assaulted by Perry during a fight a day or two before the stabbing.

"She was surprised and she didn't dislike Ms. Perry," Gilbert said of Higdon. "She never thought Ms. Perry would strike out at her."

Higdon told Gilbert that on the morning of the stabbing, Perry smirked at her. Higdon feared being assaulted again because her son had left the house and she and Perry were alone.

Gilbert said it was Higdon's actions after the stabbing that lead her to believe Higdon was not insane at the time of the crime. At one point, Gilbert said, Higdon filled a bathtub with water and considered killing herself.

"She wanted to die for what she did to Milah," Gilbert said. "She showed signs of remorse."

Contact Melanie Scott Dorsey: 313-222-6159 or mdscott@freepress.com