Washington, July 23 (ANI): Police in Aurora, Denver, has said that 'Dark Knight' massacre suspect James Holmes is refusing to co-operate with them.

Holmes, 24, has been accused of opening fire during a midnight screening of The Dark Knight Rises, killing 12 people and injuring 58, at a movie hall in Denver.

According to The Daily Express, Aurora police chief Dan Oates said Holmes had 'lawyered up' and was not talking.

Holmes has been given a public defender and is due to make an initial court appearance.

Oates said it could take months to determine a motive and police were working with FBI behavioural analysts.

He also revealed that Holmes had over 50 commercial packages delivered to his home and school address during the past four months. (ANI)