FBI chemical experts questioned at hearing for James Holmes, Aurora movie theater shooting suspect
Last Updated: 52 days ago
ARAPAHOE COUNTY, Colo. - FBI scientists are answering attorneys' questions Tuesday as the prosecution tried to prove they are expert enough to testify about homemade bomb evidence at the trial of the accused Aurora theater shooter.
James Holmes is facing more than 100 counts of murder and attempted murder, from the shooting. The jury will also need to decide if he is guilty of a crime for the booby-traps allegedly set inside his apartment. Holmes has pleaded not guilty by reason of insanity to all 166 charges. The prosecution is seeking the death penalty.
If booby-traps set in Holmes' apartment at 1690 Paris Street in Aurora had been set off, FBI Bomb Technician Garrett Gumbinner testified in a previous hearing, fires and explosions would have resulted from the combinations of napalm, gasoline, gun powder and bullets.
The defense has asked the judge to block the FBI forensic examiners from testifying for the prosecution.
During testimony Tuesday morning, FBI paints and polymers analyst Andria Mehltretter revealed she examined a glue-like substance found in Holmes' apartment. She said it was made by melting a common plastic substance.
Loud music was timed to begin 25 minutes after Holmes left the building drawing at least one neighbor to the apartment. However, instead of opening the door to the apartment, which would have triggered the explosives, the neighbor walked away. The music stopped about an hour later and the explosives were never triggered.
The second FBI forensic analyst to testify was Pamela Reynolds, who examined at two paint brushes found inside the apartment. She testified to finding iron, sodium, magnesium, silicon, sulphur, chlorine and calcium on the brushes.
In the preliminary hearing an FBI bomb technician said Holmes rigged a fuse between three glass jars that would explode. Holmes filled them, the agent said, with a potentially deadly mixture of homemade napalm and homemade thermite, which burns so hot it cannot be extinguished with water. He had also filled one jar with live rounds of ammunition.
Defense attorney Daniel King questioned Reynolds on how the minerals are examined and identified. She explained that machines examine a known, baseline chemical before processing the actual crime scene samples. It gives the teams raw data and suggested conclusions.
"The computer provides possibilities, I do independent analysis," Reynolds said.
King asked, "Ultimately, who makes the call on the substance?"
"I do," she responded.
FBI forensic examiner David McCollam testified that he flew to Denver to assist in the processing of Holmes' apartment on July 21, 2012.
"I can visually look at something and can tell if they're an explosive," said McCollam.
He said he spent 8-10 hours processing evidence inside the apartment, advising investigators how materials should be packaged and which materials should not be packaged near each other.
When asked by King if he often gets called to scenes where evidence is processed, McCollam said, "(It) happens less often than more often."
He testified under cross-examination that he identified one liquid as glycerin, a liquid that when mixed with certain chemicals can start a fire.
He also said he identified low explosives, such as black powder and thermite, but no material that he could define as a more dangerous "high explosive."
During hearings over the last week, attorneys have argued over evidence in the case.
Prosecutors want to use any evidence they can find that might show Holmes planned the attack and knew it was a crime.
The defense is arguing that interviews with Holmes were illegal because his attorney said no. The defense team has also argued that bank and phone records were obtained with flawed warrants.
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