Lab expertise helps blow open bomber case

Aug. 24, 2001

Lab expertise helps blow open bomber case


Laboratory expertise in forensic analysis played a key role in the recent conviction of “Fremont bomber” Rodney Blach, according to an Alameda County district attorney.

Blach was found guilty of 11 felony counts, including attempted murder, by a jury June 1 after an 11-week trial. He was arrested in October 1999 and charged with planting six bombs in Fremont, some targeting local government officials. Four of the pipe bombs exploded, and two were found and disarmed before they detonated, all in a 72-hour period in the last week of March 1998.

Brian Andresen of the Laboratory’s Forensic Science Center (FSC) was among the technical experts asked by prosecutor Tom Rogers, assistant district attorney, to assist in the investigation and to testify. “His work and expertise were invaluable to our successful prosecution,” Rogers said in a letter to Harry Vantine, leader of the Counterterrorism and Incident Response Program (R Division) in the NAI Directorate.

Andresen was brought into the investigation of the bombings to help investigators from the federal bureau of Alcohol, Tobacco and Firearms (ATF) reconstruct what Roger’s characterized as “the largest as well as the most electronically sophisticated domestic pipe bombs the ATF had ever encountered.”

Rogers said “the electronic aspects of the devices were beyond the expertise of anyone at the ATF.”

Andresen, whose background is in chemistry, electronics and forensics, spent hours pouring over circuit boards, electronic components and other evidence recovered from a storage locker Blach had rented in a transient’s name. In addition, timing circuits from the actual exploded bomb locations were examined at the FSC. “I was brought in to retro-engineer the electronics of the timing circuit and to discover how they worked,” Andresen said.

The discovery of the storage locker was most important and gave the prosecution the break it needed in the case. The transient, who was in jail at the time of Blach’s arrest, revealed the locker to police after recognizing Blach on a bus to court and reading about the bombings in a newspaper article.

According to news coverage of the trial, the locker contained gunpowder, books on how to make bombs, chemicals used to make explosives, electronic circuit boards and tens of thousands of pages of documents, many in Blach’s handwriting.

Nonetheless, evidence was still circumstantial and the prosecution had to link the materials found in the locker to the pipe bombs used in the attacks.

“This guy was very sophisticated in his thinking. He’s very smart,” Andresen said.

Blach is a former Chicago Police Department forensic investigator with a specialty in trace evidence.

“I was matching wits with someone who was very experienced in forensic data, law and courtroom proceedings,” Andresen added.

Although Blach never testified, he used the full extent of his experience and expertise as a police investigator in his defense, advising his attorneys on technical issues and the line of questioning to be pursued. Even before the start of his trial, Blach had boasted he would outsmart authorities, according to newspaper accounts.

Andresen testified to Blach’s “skill in making electronics and circuit boards,” the chemistry of bomb making, and the assembly of the pipe bombs.

The unique timing circuit system consisted of a digital watch attached to a small relay circuit that could be set to go off months in the future, a homemade circuit board and other common electrical components. Some devices were detonated using a modified car sparkplug. “It was a very elegant approach,” Andresen said. “The design of these devices showed on-the-edge sophistication.”

Resolving how a sparkplug was adapted to serve as a detonator turned out to be a key to overcoming the defense’s contention that the sparkplug could not conduct the detonating electrical signal in the configuration presented by the prosecution. However, Andresen was able to show that the sparkplug’s central electrode rod had been elongated and fitted with a small machine screw to pass an electrical signal. He made working prototypes of all the timer circuit boards and sparkplug components for courtroom testimony.

Despite the sophistication of the design, the circuit boards were clearly “homemade.” In particular, Andresen discovered that the bomb circuit boards had been inexpertly soldered on the wrong side. This finding was important to linking the pipe bombs to Blach, who, while technically sophisticated, was inexperienced in electronics engineering.

Rogers said in a phone interview that Andresen’s “specialized knowledge of electronics was a “tremendous benefit to us” by providing the prosecution with a “rebuttal to experts.”

“Brian spent much of his own personal time working on this,” Rogers noted. “I’m very grateful to him.”

Andresen said this case is similar to the kind of terrorist activity the Laboratory — NAI specifically — is dedicated to thwarting as part of its national security mission. “A case like this is valuable real-world training for us.”

Amazingly, no one was killed or severely injured in the bombings, although extensive property damage was caused by two of the bombs that exploded. The first bomb exploded on the front porch of Fremont Police Chief Craig Steckler. Fremont City Councilman Bob Wasserman was another target.

“These bombs were big and extremely powerful,” Andresen said. “It’s very unsettling to known that people want to cause such devastation. It’s scary.”

In his letter to Vantine, Rogers said Blach presented a great danger “to the lives of innocent people…This defendant had the ability and propensity to commit a mass murder such as what was perpetrated at Oklahoma City.”