Samuel John Dieteman, one of two arrested in the serial shooter case, is seen during his initial court appearance in Maricopa County court at the jail, Friday, Aug. 4, 2006, in Phoenix.

One of the two suspects in a series of apparently random late-night killings discarded a trash bag in which police found a map with red and blue dots representing the locations of the attacks.

The bag also contained an expended .410-gauge shotgun shell and a piece of paper referring to serial violence, according to a probable cause statement released Friday night.

The trash bag had been tossed into a bin at the suburban Mesa apartment complex where Dale S. Hausner and Samuel John Dieteman lived, the report said. The men, accused of shooting two dozen people, including six fatally, were arrested late Thursday after police tailed them for a week.