TAMPA — A sugar rocket enthusiast pitted his experience and field testing against that of an FBI chemist and federal explosives expert Thursday in evaluating the danger posed by PVC pipes and chemicals recovered at the time of Youssef Megahed's arrest.
After the prosecution rested its case in U.S. District Court, one of the first defense witnesses was James Yawn, the Career Resource Center coordinator at Santa Fe College in Gainesville. Yawn also teaches a two-day class called "Rocket Science 101." He said building model rockets has been his hobby for over 30 years.
He spent much of the day testifying about his attempts to duplicate tests FBI experts did on replicas of the PVC pipes found in Megahed's car. He was called to demonstrate that the chemicals in the car are commonly used to propel model rockets.
The FBI had used the same material to show that it could be used as an improvised bomb.
Jurors saw about a dozen short video presentations of Yawn making a potassium nitrate mixture similar to the one described in the FBI's report. He stuffed the mixture into PVC pipes and ignited them with safety fuses.
In most cases, the devices only expelled gas. In two tests, the pipes went airborne. Yawn said he would give his student a "generous D" for the rocket that went airborne slightly and a C grade for the rocket that launched higher.
Adam Allen, Megahed's attorney, has described the PVC pipes as homemade fireworks or model rockets. Megahed has denied knowing they were in the trunk of the car when he and fellow University of South Florida student Ahmed Mohamed were stopped for speeding in Goose Creek, S.C., on Aug. 4, 2007.
Megahed is charged with illegal transportation of explosive materials and a destructive device. FBI experts testified that the materials found in the car could be dangerous.
Assistant U.S. Attorney Jay Hoffer attempted to lessen Yawn's testimony by calling to jurors' attention that Yawn has no training in explosives and no degree in science.
When Hoffer asked Yawn if he regarded one of the items he built to be a firework, he paused.
"I hesitate because there are legal definitions of a firework," Yawn said, adding, "It uses fire. It does work." Yawn later said he would call the device an "attempted rocket."
The jury will weigh Yawn's testimony against the FBI chemist with 30 years of experience and an FBI explosives expert who testified for the prosecution. The FBI experts said the pipes were neither rockets nor fireworks.
Earlier Thursday, U.S. District Judge Steven D. Merryday decided jurors wouldn't see a 44-minute video recovered from Megahed's friend's laptop computer that shows Qassam rockets launching in the Middle East.
Merryday didn't explain the ruling, except to say the prosecution and defense agreed that the video was on Mohamed's laptop.
An FBI computer analyst testified that the video was viewed on the laptop minutes before Mohamed and Megahed were pulled over by police.
A sheriff's deputy who stopped the car found Megahed holding the laptop and unplugging wires from it as he approached the car.
Deputies searched the car and found PVC pipes with a potassium nitrate explosive mixture in the trunk after a deputy became suspicious of their behavior.
Mohamed is serving a 15-year prison sentence for providing material support to terrorists. He pleaded guilty to posting a YouTube video showing how to turn a child's toy into a detonator.
Outside the jury's presence, prosecutors had argued for admission of the video as evidence. They said Megahed likely watched it, and prosecutors wanted to use it to bolster their claims that Megahed had an interest in explosives.
The judge described the video to jurors as showing military-style rockets in different settings "being launched with propellants of unknown composition."
Trial resumes Monday.
Kevin Graham can be reached at firstname.lastname@example.org or (813) 226-3433.