He bought the Ruger a week before the shooting. Colorado banned the sale of magazines over 15 rounds so they almost certainly were 15 rounds.
That is likely, but it has not been confirmed.
He also had another gun, supposedly a for conventional pistol.
The police are sitting on the information.
They have also had over 100 interviews of the murderer, but "have not determined a motive".
Far left woman police chief in a far left polity.