His lawyer, Richard Brown, said Mr. Morgan would now get the mental health treatment he needed.

“Key to this case is that the psychiatrist hired by Connecticut found that my client could not conform his actions to the law,” Mr. Brown told reporters after the verdict.

The prosecutor, Timothy Liston, did not immediately comment.

During the trial, Madelon Baranoski, a forensic psychologist and Yale University professor, testified she had evaluated Mr. Morgan and determined that he had paranoid schizophrenia. She said he had delusional thoughts that included prison guards reading his mind, video of his thoughts being shown to his family and fellow inmates monitoring him from strategic locations.

Dr. Baranoski also said Mr. Morgan’s mental illness would not be immediately apparent to others.

Mr. Morgan apparently met Ms. Justin-Jinich at New York University in the summer of 2007, the police said.

Ms. Justin-Jinich was working at the Red and Black Cafe in Broad Street Books near Wesleyan when Mr. Morgan, disguised in a wig and glasses, walked in and shot her seven times with a handgun before fleeing.