Prosecutors routinely subpoena a defendant's co-workers, friends and even family members -- but this time they were barking up the wrong tree. In an Arkansas murder trial, prosecutors ordered five-year-old Murphy Smith to court for pre-trial testimony. But a deputy wouldn't let Murphy into the courthouse: no dogs allowed. Officials had sent out subpoenas to anyone who had contact with Albert Smith while he was in jail awaiting trial. The murder suspect had written his dog a letter from his prison cell. That landed the pooch on the witness list. A prosecutor says Murphy "was friendly enough" and likely "would have been a very cooperative witness." But she says the appearance wasn't necessary. Smith is charged with killing a man who had a relationship with his former wife.