A former girlfriend of Aurora, Colorado, theater shooter James Holmes testified in his mass-murder trial on Wednesday, noting that he sent her messages saying he wanted to kill people. Gargi Datta said she never took Holmes seriously and suggested he get help, not realizing that he would later carry out an attack on a movie theater that left 12 people and 70 others injured. Datta said she met Holmes in 2011 in graduate school, describing him as a bright but shy neuroscience graduate student. Prosecutors have said their breakup in February may have sparked the shooting five months later. Holmes has pleaded not guilty by reason of insanity.