Sept. 7, 2011 -- A former friend of Michelle Le, the missing California nursing student who disappeared in May, has been arrested and charged with her murder.

Surveillance video, cellphone records and DNA samples led to this morning's arrest of Giselle Esteban, according to Lt. Roger Keener of the Hayward police department.

Le disappeared on May 27 from Kaiser Permanente Hayward Medical Center in northern California as she was walking from her car to the garage, according to ABC News afilliate KGO. Police believe she was murdered.

Blood stains belonging to Le were found on the interior of Le's car and matched those found on the bottom of a pair of sneakers in Esteban's home, according to Keener.

Security video from the parking garage in which Le was last seen also showed Esteban in the garage before and after Le's arrival there and led police to believe that Le was assaulted while there, Keener said.

Hayward police and the FBI also tracked the cellphone movements of Le's phone and, later, Esteban's phone in the hours after her disappearance, and saw that both cellphones moved around Alameda County in about the same path and timeframe, he said.

Police said that though they believe they have solved one part of the crime against Le, they are still committed to finding Le and figuring out what happened to her.

"Today does not mark the end of the investigation," Keener said. "We will not consider this investigation complete until Michelle is found."

"Some of the questions about how [Le] met her demise may not be known until she is found," he added.

Keener would not elaborate on the relationship between the pair or speculate on a motive.

The Oakland Tribune previously reported that Esteban's former boyfriend, with whom she had a child, had a relationship with Le. The boyfriend filed a restraining order against Esteban just three days prior to Le's disappearance, citing Esteban's erratic behavior and threats of killing herself, according to the report.

Le's family made a statement following the arrest, saying that Esteban, who's been a suspect since May, "dragged this out longer than it had to go," and that their "primary concern was and is and always will be to find Michelle and bring her home with us."