Previous stories:

Sheriff's Office to review itself, published 02/08/2012Too much pedal on the metal, Editorial, published 02/08/2012Deputy reaches 133 mph during pursuit, published 02/07/2012Chase end, high-five in new video released by Sheriff's Office, published 02/04/2012

Charleston County Sheriff Al Cannon is asking the State Law Enforcement Division to widen the scope of its investigation into the Jan. 30 high-speed chase that ended with the arrest of Timothy Shawn McManus.

In a letter composed Wednesday to SLED Chief Mark Keel, Cannon asks the state agency to review the actions taken by himself and deputies involved in the chase, and to "investigate the pursuit itself in relation to our policies."

Many questions have been raised concerning the chase and its aftermath: a deputy reported he reached speeds of 133 mph while heading to the chase scene; video shows deputies possibly using excessive force to subdue McManus after he left his vehicle; and Cannon admits that in the heat of passion he slapped McManus while the suspect was handcuffed and seated in a patrol car.

Because SLED routinely probes incidents in which law officers use their firearms, the state agency is already looking into shots that Cannon and two deputies fired to stop the speeding truck. The truck reportedly reached 120 mph, and avoided several placements of "stop sticks" on highways east of the Cooper. Cannon and the deputies shot out at least two tires to force the Dodge Ram truck to halt on dirt roads in the Francis Marion National Forest.

A day after the chase, Cannon admitted that he chided McManus for endangering lives of many motorists and pedestrians, and slapped him across his face. Cannon informed SLED then and asked that they probe his actions as part of their investigation.

In his letter, Cannon noted that because of his personal involvement in the chase, the Sheriff's Office may not be able to conduct a non-biased probe on its own.

"We believe this case would be better served by one large-scale investigative process, and since your agency is already involved , it seems logical to ask your consideration to expand your efforts," Cannon wrote.