The lone undercover agent in a sting that sent dozens of black people to prison on bogus drug charges in Tulia (search) was convicted Friday of one of two perjury counts.

Tom Coleman (search) was acquitted of testifying falsely in a 2003 hearing that as a sheriff's deputy he never stole gas from county pumps, but he was found guilty of saying that he didn't learn about the theft charge against him until August 1998.

Jurors were to begin hearing evidence in the penalty phase of the trial later Friday. Aggravated perjury is a third-degree felony and carries a maximum 10-year sentence and $10,000 fine.

Coleman had no noticeable reaction as the verdict was read, but some Tulia defendants in the courtroom bowed their heads as the verdict was read.

Coleman arrested 46 people, most of them black, in the small, mostly white farming community of Tulia. He worked alone and used no audio or video surveillance, and no drugs were ever found, but 38 defendants were convicted or reached plea deals.

Gov. Rick Perry (search) pardoned 35 of the defendants in 2003, after an investigation into the drug cases was launched amid charges they were racially motivated. It was during the investigation that Coleman made his false statement in court.

Last year, 45 of those arrested split a $6 million settlement of a civil rights lawsuit against Coleman and the 26 counties and three cities involved with the drug task force for which he worked.