Dr. Creson told the jury he believed brain damage from a childhood head injury caused Quintero to have a severe mental breakdown when /*Officer Johnson*/ arrested him during a routine traffic stop, further playing into the defense's claim that Quintero was temporarily insane when he shot and killed the officer.
"His brain is crippled in terms of how it can function in society or life in general," testified Dr. Creson.
KTRK legal analyst Joel Androphy believes expert testimony from the defense may not be enough to convince jurors. He says it's a difficult issue to sell to a conservative jury.
"A juror, in order to go along with this theory of the defense, has to want to acquit this guy," he told us. "They have to want to help him and this would give them some justification. But your average person is not going to be swayed by it."
Prosecutors sought to discredit Dr. Creson's testimony during cross examination. They argued Quintero knew exactly what he was doing and that he simply acted out of anger.
"He told you he understood what he did was wrong?" asked the prosecution.
Dr. Creson answered, "He told me something to that effect, yes."
The prosecutor came back with, "Even if I have anxiety disorder and an alcohol problem, I can still act out of anger?"
"Yes," answered Dr. Creson. "It predisposes you."
A neuropsychologist was called by the defense before they rested.