The murder trial of Tavon Donya Sands ended abruptly in a mistrial yesterday after a witness testified that an investigator showed him a series of photos that included the 21- year-old Columbia man's picture - information that prosecution and defense attorneys said caught them by surprise.

Howard Circuit Judge Raymond J. Kane Jr. halted the proceedings during the trial's first full day of testimony, saying a mistrial was the only remedy.

The issue, the lawyers said yesterday, was one of discovery - rules requiring that the state turn over any evidence relating to guilt or innocence of a defendant to the defense.

Sands is charged with first-degree murder, armed robbery and related offenses stemming from the fatal shooting of 23-year-old DeShawn Anthony Wallace during a botched robbery Jan. 25 in Columbia.

The testimony that ended this week's trial came near the end of the day yesterday after the state's eighth witness, Gaston Leonard Davis, said he saw Sands and two other men get out of a white Cadillac near his apartment building. He said he watched as Sands put an object in his waistband and headed for the nearby Stevens Forest Apartments.

Davis later acknowledged that he had been shown photographs, including one of Sands, by police after the shooting. After that disclosure, defense attorney Joseph Murtha requested the mistrial.