Report: No electronic flaws in recalled Toyotas

>>> we have an update tonight being billed as the final word from the government on the investigation into problems with toyotas speeding out of control. almost a year after an eight million vehicle recall and $50 million in fines against the company, government investigators said they found no sign that electronic defects played a role in the problem. would you believe it was the floor mats the whole time? well, not everybody does. and our own tom costello with us tonight with more on this from washington. tom, good evening.

>> reporter: hi, brian. the government says it put its top scientists on that, and in fact it says at least some of those unattended accelerations were caused by people hitting the gas instead of the brake. for ten months, investigators from nasa and the transportation department have been in the lab and on the track, looking into whether toyota 's stuck accelerators might involve an elusive electronic problem. a sort of ghost in the machine . today the government said there is no such evidence.

>> our conclusion is this. toyota 's problems were mechanical, not electrical.

>> reporter: that confirms toyota 's findings. it's already recalled eight million toyota and lexus cars and fixed sticking floor mats that it blames for unintended acceleration. toyota 's problems became front page news in 2009 . after the fiery crash in california killed a california patrol officer and three family members. soon there were 3,000 complaints from drivers claiming their gas pedals also had gotten stuck.

>> all of a sudden my car took off out from under me and slammed into the building.

>> on behalf of all --

>> reporter: rhonda smith told congress her lexus had accelerated to 100 miles per hour. terrified with both feet on the brake, she called her husband.

>> i knew he could not help me, but i wanted to hear his voice one more time.

>> reporter: finally she was able to stop. annie zoll died after her camry flew off a california cliff. her family's attorney today was skeptical.

>> i do believe the root cause is electromagnetic interference.

>> reporter: because investigators examined fewer than 75 cars, some consumers are also skeptical.

>> you're looking for a needle in a haystack , and we don't have the time or money to find that needle.

>> reporter: it's a sigh of relief for many automakers. this is not the final word. the national academy of sciences is also investigating. its report due out in the fall. brian, of the 93 alleged cases of people dying because of unintended acceleration. the government says it's only been able to verify five of those. back to you.

>> tom costello in washington tonight.