OAKLAND, Calif. -  

A murder trial is under way for a woman accused of stalking and killing a San Francisco Bay Area nursing student.

Alameda County Prosecutor Butch Ford argued Monday that Giselle Esteban killed former friend Michelle Le last year out of "jealousy, hatred and rage," because she blamed Le for ruining her relationship with Scott Marasigan, her daughter's father.

Esteban and Le were former friends from their days at Mount Carmel High School in Rancho Penasquitos.

Ford said Esteban texted Marasigan that "punishment would be swift" if he didn't cut Le out of his life. Ford also said that Esteban went to great lengths to hunt Le down, including stealing a security badge and a class roster from Le's nursing school.

But Esteban's defense attorney, Audrea Aura, admitted while there's "a mountain of evidence" against her client, Esteban did not plan to kill Le, but snapped due to "extreme provocation and heat of passion."

Esteban has pleaded not guilty.

Le was reported missing on May 27, 2011. Her remains were found in a remote area of Alameda County nearly four months later, several miles from the hospital.

Esteban told Bay Area TV station KGO in June 2011 that she hated Le because Le was friends with the father of Esteban's 5-year-old daughter. But Esteban denied having anything to do with Le's disappearance.