About a dozen human rights activists and people who had been stunned by Tasers gathered yesterday to call for a moratorium on the use of the weapon by police.

The Taser garnered increased attention locally last month after the death of Andre Thomas, of Swissvale, and the case of Jason Schmidt, of Observatory Hill, who might be permanently disabled. Both men were stunned by Tasers during altercations with police.

Allegheny County District Attorney Stephen A. Zappala Jr. announced he would form a working group, along with Medical Examiner Dr. Karl Williams, to study the weapon's use by county police forces.

The activists used Mr. Zappala's office as a backdrop to stage the news conference asking for swift action by the group, which has not yet been formed. The Black and White Reunion, a group working to end racism in Pittsburgh, hosted the event.

Celeste Taylor, spokeswoman for The Black and White Reunion, said the Taser's effects must be studied further, and her group is seeking better training and uniformity in regulations on Taser use for the county's police departments.

Others spoke about police abuses of the weapon, including two men who said they had been stunned by Tasers without cause.