it says colusa county sheriff's office, colusa, california, no street address and in the upper left-handorner says ayala case and then there are eight stamps on it. it was pretty light. it was way too much postage. >> reporter: because inside was just a single sheet of paper. an open letter to the cops. what did that letter say? >> basically it was claiming responsibility for the bombing. >> the letter full of misspellings and bad grammar had been written on a label maker, then photocopied. its author claimed to be a military trained contract killer who had been hired to kill roberto over a mexico deal gone wrong. >> that it was ms-13 behind it. >> what the heck is ms-13? >> it's a violent el salvadorian criminal street gang. >> reporter: and that roberto was supposed to be a target of this group? >> the letter implied roberto had messed with a drug cartel and that ms-13 had been contracted. >> the author of the letter taunted the detectives, writing the lab results would find military-grade powder but no dna, which was true so far. the point of the letter wrote its author was a warning.

he found a sandstone in colusa county, which adorns the fagade currently. the story gets really interesting. in the 70s the owners at the time, there was some damage on the building that they had to repair. they brought on a firm to do that. they applied material to it which had the impact of discoloring the color, but also because of the sandstone being very porous, you cannot reverse that action. the only way to adorn it was to paint it. we spent a lot of time working with the port of san francisco, and local heritage groups, we found an old piece of the sandstone itself that had not been discolored. we matched that, worked with sherwin williams, and they came up with the for perfect mix that matches the original color. >> was there any debate about trying to restore that original sandstone, was that feasible? >> unfortunately that was impossible. the corrective work that was done in 1970s was irreversible. >> and i understand that there are going to be some upgrades to the clock tower as well what kind of work are you doing? >> a little early to tell wha

it looks cnn -- it was a climate of colusa. cnn was in on the joke.hey carried the party line 100% of the way. there are a lot of questions you could ask about whether you really believe if you make these changes if the storm off the east coast would be smaller, there would be fewer hurricanes, whether any questions like that at all? the trillions and trillions of dollars that really radical and extreme ideas and so many of them, none of this question the budget, was never a question, none of it was under question. it was classic. >> tucker: it was perfect in that way. good to see you tonight, thank you. joe biden was also there tonight. he is the reported democratic frontrunner. he didn't say much about global warming that was interesting. not more interesting than the story he himself created by being there. it wasn't could put one point he was trying to answer a question and he seemed to lose his train of thought completely. >> that saves billions of gallons of gasoline. i mean billions of 2. -- i think it's $2.3 billion worth of excusing, $500 bil

next time you make a cup of tea scientists say you might want to go with the paper tea bag gorgeous colusae to use a plastic tea bag which apparently is the most common form shards of plastic. >>might end up in your berle, gray or long t that is the latest from a new study out our research is removed that t from the bag before putting it in boiling water and ended up finding just one bag get this released of billions of what they call microplastic particles into the car. quite a bit of plastic a as it is enough to equal the weight. >>a new study says too much exercise may lead you to make poor food choices. researchers compared brain scans of athletes who train normally to those who over trained. the ones who over trained showed more fatigue in the cognitive control part of the brain system which helps to lay self-gratification you know the part of the brain that would say to you no you don't need that second fudge sundae it was published in the journal current biology. >>as making some pretty cool boarding passes come on cars the weather's perfect... family is all together and we switched