HOUSTON -- A jury found an illegal immigrant guilty of killing Houston Police Officer Rodney Johnson, KPRC Local 2 reported Thursday.

Juan Leonardo Quintero, 33, was found guilty of capital murder. He pleaded not guilty by reason of insanity.

Prosecutors will seek the death penalty.

In closing arguments, prosecutor John Jordan pointed at Quintero and told jurors, "You all will get to decide by your verdict what I told you two weeks ago -- he ain't insane, he's just a cold-blooded killer."

Jordan said that Quintero shot and killed Johnson on Sept. 21, 2006, after a traffic stop in southeast Houston because he was afraid of being arrested and could have faced deportation to his native Mexico.

During the trial, the defense told jurors that Quintero suffered from a mental defect that was caused by a childhood fall.

During closing arguments Thursday morning, defense attorney Danalynn Recer stuck to that theme.

"Mr. Quintero has a mental defect such that he doesn't know his actions at the time were wrong," she argued.

The courtroom was overflowing with people and emotions during the final arguments.

Johnson's widow wiped away tears but was comforted by many of his fellow officers and family members who also sat through the emotional courtroom drama.

The punishment phase of the trial begins Tuesday.