A bomb threat was called in to the McLennan County Sheriff's Office at 8 a.m. Friday, prompting the evacuation of the McLennan County Courthouse and nearby buildings in Waco. Deputies conducted a primary and secondary search of the courthouse, the district attorney's office, and the annex using a K-9 unit before giving the all clear. All court dockets were canceled for the day by order of the county judge, leaving residents with scheduled court …