article_snippet: There has been no evidence that the two brothers actually tested and tried out making a bomb and detonating a bomb," CNN National Security Analyst Juliette Kayyem said.
article_snippet: No one has been publicly named as a possible co-conspirator.
article_snippet: There wasn't trace evidence -- black powder from fireworks -- found in either home, their cars or anywhere associated with their, the court documents said.
article_snippet: Marks said investigators didn't find circuit testers.
article_snippet: You want a separate circuit tester in order to test the functionality of the components without it being hooked up to the actual device, for your own safety," Dzhokhar Tsarnaev said.
highlights_snippet: There was no evidence the brothers ever tested the brothers bombs before using their bombs, CNN analyst says .