HOUSTON -

Stabbing suspect Dylan Quick is undergoing a mental health evaluation as officials try to figure out what led him to commit Tuesday's attack at Lone Star College Cy-Fair.

Meanwhile, Local 2 spoke to a mental health expert to get a glimpse into what may have led Quick to use a razor-utility knife to attack people at random.

Similar to the shootings in Newtown and the Colorado movie theater rampage, mental health experts are not surprised that Quick told deputies that he had been planning the attack. 

"Some of these people who do these crimes, they don't have a specific person, it is not revenge against a particular bully for example -- it is against society that they hold responsible for their being angry and underneath that, so miserable," said Dr. Harvey Rosenstock, a Bellaire psychiatrist. 

Neighbors say Quick was quiet and didn't appear to have many friends. Others at the school library who knew him as a polite student were surprised to hear he is a suspect.

"You can look wonderful, in terms of polite. Say 'hello' and 'good morning,' but you are not talking with anyone... There is an existence side by side but internally the rage is boiling and it is crescendoing out of control," said Rosenstock. 

Quick told deputies he had fantasies about stabbing people since he was 8 years old, according to Harris County Sheriff Adrian Garcia.

Quick chose a different weapon from other school attacks. "I see the knife as the infliction of pain and the drawing of blood. It is an immediate symbol of this type of rage and getting back at society," said Rosenstock.

In almost all these types of attacks, Rosenstock said that the suspects are feeling they are not accepted or experiencing chaos they can't control.  "Without help and treatment we can become someone who is extremely dangerous to society," said Rosenstock.