We affirm.


2
Drug Enforcement Administration Special Agent Ruric Staton received on April 20, 1976 information from a confidential informant concerning a black man and woman who would register at an El Paso Rodeway Inn, intending during their stay to procure a quantity of heroin.  The only description of the two was that the male would have gray hair and a beard and would be wearing a hat similar to a sailor's cap turned inside out.  Agent Staton placed the Rodeway Inn under surveillance and discovered that a couple meeting the given description were staying in a room registered under the name of Ken Watson.  Watson was later determined to be an alias for Montgomery and his companion was learned to be Ruby Swartz.  On April21, Agent Staton was joined at the Rodeway Inn by Customs Air Detail Agent Ruben Gomez.  The joinder of Gomez and Staton at this time was coincidental.  The possibility of a connection between this surveillance and Gomez's earlier work was not discovered until later.  No proof of the purpose or results of Agent Gomez's previous investigation was offered at trial.  Later on the 21st Montgomery and Swartz were seen together with another black, Thomas McGarrity.  McGarrity was registered under the alias of Tim McNary.  The three were seen together near the pool area, taking pictures of one another and otherwise indicating that they were acquainted.


3
Agent Gomez overheard a phone call placed by Ruby Swartz in which she stated that she was staying