OAKLAND, Calif. (AP) – Prosecutors have added charges that could qualify a man for the death penalty if he’s convicted of killing 18-year-old Nia Wilson at a train station in Northern California.

The Alameda County District Attorney’s Office added the special-circumstances enhancement of “lying in wait” to the charges against John Cowell.

He didn’t enter a plea during the court hearing Wednesday.

Cowell is charged with murder in the fatal stabbing of Wilson last month as she changed trains at a subway station in Oakland.

Cowell also is charged with attempted murder in the attack that wounded Wilson’s sister.

The defendant’s attorney, Brendon Woods, says he’s deeply concerned that prosecutors will seek the death penalty “for someone that has severe, severe mental illness.”