Maryland state trooper testifying in the drunk driving trial of Kevin Cooper acknowledged today to a Talbot County Circuit Court jury that Cooper may not have been traveling at an illegal speed at the time of the collision that killed five members of a Montgomery County family last Christmas Eve.

Cpl. Al Liebno said under cross-examination that some of the calculations he used to determine Cooper's speed when his car crashed into the automobile of Martha Proctor were based on "estimations." Actual measurements of things such as the weight of Cooper's car were not made.

The speed of Cooper's car is crucial to the state's effort to prove that he was driving recklessly. Carroll County State's Attorney Thomas Hickman stated at the beginning of the trial that the government would prove Cooper was driving 70 miles per hour at the time of the accident.

Liebno testified that if he substituted some new estimates in his calculations, the results could show Cooper was traveling as slow as 52.8 miles per hour at the time of impact.

"All you've shown the jury here today was based purely on an estimate--a guess, isn't that right, Cpl. Liebno?," defense attorney Christopher D. Ohly asked.

"That's correct," Liebno responded.