As Arlington County detectives continued to investigate the shooting death of 24-year-old Paul Zeller outside the Pentagon Row shops last week, the former soldier's father said yesterday that his son would be buried this morning in his home state of Colorado. -snip- "It's been very hard for us," said Zeller, a retired Navy chaplain who teaches at a seminary in Westcliffe. "We don't have any answers. . . . The police haven't told us anything except to avoid speculating about what happened." Police said Zeller was fatally shot at close range outside the upscale shopping center just after midnight Friday....