Baltimore

After sending the NCIS team a message in the form of the eye in "Two-Faced" - revealed to belong to a person whose identity is classified - the Port to Port Killer seems to have struck with another victim: Danny Price, formerly DiNozzo's partner in the Baltimore P.D. homicide squad. Believing that the Port to Port Killer may have a connection to DiNozzo, the team begins to concentrate on his time in Baltimore. Inconsistencies in the autopsy reports lead them to suspect there is a copycat killer on the loose, and it is eventually revealed that a mistake caused by Palmer in a report sent out to law enforcement agencies gave the copycat killer the necessary knowledge to replicate the Port to Port Killer with near-perfect accuracy. Because of Palmer's mistake, NCIS is able to catch a would-be copycat before he can kill, as well as find Price's murderer - DiNozzo's former captain in Baltimore.