Le, a 26-year-old San Mateo woman who was attending Samuel Merritt University in Oakland, disappeared from Kaiser Permanente Medical Center in Hayward on May 27. Her body was found in a remote area between Pleasanton and Sunol on Sept. 17.
Esteban, a 27-year-old Union City woman who attended high school with Le in San Diego, was charged with Le's murder on Sept. 8 -- before Le's body was found -- based on DNA evidence and cellphone records.
An Alameda County criminal grand jury indicted Esteban on an identical murder charge on Dec. 14 at the end of a three-day hearing. Prosecutors sought the indictment to try to speed up her trial.
The indictment allows prosecutors to bypass the step of having a preliminary hearing at which a judge determines if there is enough evidence against a defendant for a case to proceed to trial.
According to the 470-page transcript of the panel's proceedings, Scott Marasigan first met Esteban, dated Le briefly, although they didn't have a sexual relationship, and then developed a more serious relationship with Esteban, ultimately having a daughter with her on Oct. 31, 2005.
However, Marasigan later broke up with Esteban and was awarded full custody of their daughter in September 2010, according to the transcript.
Prosecutor Butch Ford told the grand jury that Marasigan continued to be a non-romantic friend of Le but "Giselle did not want him to have a friendly relationship with Michelle in any form, shape or fashion."
Ford said, "Giselle would not leave the issue of Michelle alone and wanted to control Scott, wanted to prevent him from having any sort of contact at all" with her.
Esteban would threaten Marasigan, talk about the consequences of what would happen if he didn't stop seeing Le and told him "that the punishment would be swift" if he continued seeing her, according to Ford.
The prosecutor says in the days before May 27, "Giselle was so enraged that she began to essentially hunt down Miss Le."
Ford said, "We intend to prove that Giselle Esteban had become successful and actually stalked Michelle to the Kaiser facility in Hayward, attacked her in the parking lot, threw her body into Michelle's car and drove her away from Hayward, ultimately out to the Pleasanton-Sunol Valley Road area, and ultimately, through sort of a makeshift grave, buried Michelle's body out there."
Fellow prosecutor Robert Warren told the grand jury that text messages that Esteban sent to Marasigan "show that this hatred, this obsession (about Michelle Le) that was within Miss Esteban was continuous from November of 2010 until May 27, 2011."
Referring to Marasigan, Warren said, "No matter how many times he denied any relationship between himself and Miss Le, Miss Esteban refused to believe him."
In her text messages Esteban said Le "will pay with her life" and "would not be a problem for much longer," Warren told the panel.
Warren said it's not entirely clear how Le was killed but circumstantial evidence such as Le's hair and blood indicate that Esteban assaulted her in the parking lot at the Kaiser facility and then placed Le into her own car, in which Le continued to bleed.
"We know an injured Miss Le was in her own vehicle bleeding," Warren said.
He said, "She continued to bleed and whatever the means of her demise they were significant enough that the only thing we found (when Le's body was located in September) were her remains, skeletal remains."
Marasigan told the grand jury that he had a volatile relationship with Esteban.
He said Esteban "had quite a number of suicide threats" and "was very manipulative and kind of used that as a power play."
Marasigan also said she was briefly committed in facilities based on her threats to harm herself and at various times had been diagnosed with manic depression with psychotic features as well as with a form of bipolar disorder.
He told the grand jury that Esteban "was exhibiting unstable behavior" in the days before Le disappeared and he filed for a temporary restraining order against her only three days before Le went missing.
Esteban was arraigned on Dec. 20 on the murder charge contained in the grand jury indictment. She is scheduled to return to court on Jan. 20 to enter a plea.
After Esteban was charged in September, a number of her hearings were postponed because of medical issues related to her pregnancy. She has since given birth, although the date hasn't been disclosed.
Marasigan told the grand jury that he heard that Esteban gave birth the week before Thanksgiving.
The name of the father of Esteban's baby hasn't been disclosed and Marasigan has said he's not the father.
Esteban's lawyer, Andrea Auer, declined to comment on the case Friday.