FORT WORTH, Texas (AP) _ The chief of police on Saturday said he wouldn't automatically resign in the wake of a videotape showing one of his officers beating a man in custody.

Fort Worth Police Chief Thomas Windham's remarks came as FBI Director William Sessions said about half the civil rights cases investigated by his agents involve allegations of police brutality.

In an address to the National Association for the Advancement of Colored People, Sessions praised citizens who have made videotapes of police beatings in Los Angeles and Fort Worth.

''I am delighted that those videos do appear because they are very graphic'' and show the public the extent of such brutality, Sessions said in Houston.

In March, following a national outcry over a videotaped beating of an unarmed motorist by four Los Angeles police officers, Windham had said he would resign if such a beating happened in Fort Worth.

On Friday, Fort Worth police Officer Edward James Parnell III was charged with assault with a deadly weapon for allegedly beating a car theft suspect with a baton Wednesday. Parnell was suspended with pay.

Windham on Saturday clarified his earlier statement.

''If we had the mayor calling for my resignation and other influential and not-so-influential citizens calling for my resignation, I would resign,'' Windham said. After the Los Angeles incident, Mayor Tom Bradley called for Police Chief Daryl Gates to step down.

''If you have an irreparable situation, I think the police chief should move aside and let someone else take over,'' Windham said. ''So if resigning needed to be done, I'd do it.''

Meanwhile, the car theft suspect in Wednesday's beating, Ernest Alvin Anderson, is expected to surrender to police Monday for questioning in an attempted murder last month, said Lt. Alvin Allcon.

Anderson, 21, faces four charges of criminal mischief, theft, resisting arrest, and evading arrest in Wednesday's incident. Fort Worth police issued an arrest warrant on the attempted murder charge Friday after Anderson left the Tarrant County Jail on $2,500 bond. Allcon couldn't provide details of the attempted murder case.

Anderson's attorney, Mark Daniel, would not comment on either case.

In Wednesday's beating, Anderson was in Parnell's patrol car en route to a Fort Worth jail when he allegedly kicked out a rear window and tried to jump out on Interstate 30.

Parnell stopped the car along the highway and can be seen beating Anderson while he's hanging out the window and slumped against the car. A woman taped the beating from a home near the highway and gave the tape to a television station.

Unlike the March 3 beating in Los Angeles, which involved a black suspect and white police officers, both Parnell and Anderson are black.

''The strongest feeling I had was disappointment, great disappointment that a Fort Worth police officer would resort to using such tactics in such situations,'' Windham said.

''There was nothing I could see about the incident that would either necessitate or justify the manner in which the officer was utilizing his baton,'' he added.

In an interview Friday with television station KXAS, Parnell, who joined the force in 1988, said he expects to be cleared.

''I believe in the end of the investigation, I'll be found not guilty of all charges,'' he said.

Assault with a deadly weapon carries a prison sentence ranging from two to 10 years, plus a $1,000 fine. Parnell was released on his own recognizance.

Anderson told KXAS earlier that he had become angry in the police car because he wanted his handcuffs loosened.