File photo of Michelle Le

ALAMEDA COUNTY–

Giselle Esteban, Michelle Le’s convicted killer, was sentenced to 25 years to life in prison Monday morning.

A former nursing student, Le was last seen in May 2011 at her nurse training shift at Kaiser in Hayward, and initially her case was treated as a missing person.

Investigators questioned Esteban — a former friend of Le’s — right away, but did not file charges against her until September 2011. They had to gather enough evidence to charge Estaban without Le’s body.

However, about a week after charging Esteban, Le’s body was found in a secluded area east of San Francisco Bay.

Esteban was convicted of murdering Le on Oct. 29.