The remains of a pregnant teenager were found in a landfill after months of searching, authorities said Thursday.

Anyssia Escamilla, 17, disappeared in May and shortly afterward her boyfriend was charged with her death.

Authorities aided by dogs covered two landfills before finding the body in a dump in Corona, police said.

Escamilla, the mother of a 3-year-old son from another relationship, was reported missing on May 11 when she failed to return home from Bloomington High School.

Police said her boyfriend, 18-year-old Jesus Avitia Jr., told detectives he killed Escamilla and placed her body in a trash can near his home. Her body apparently was never seen by trash-truck drivers who use a robotic arm to empty cans.

Avitia has pleaded not guilty to murdering the girl and her 3-month-old fetus. The charges carry a special-circumstance allegation of multiple murder that could make him eligible for the death penalty.

Detectives did not know how Escamilla was killed because Avitia gave conflicting statements, police said.

Investigators also were trying to determine a motive.

Escamilla's family said Avitia's family didn't approve of him seeing a girl who already had a child. Her parents said the two had been dating for about a year.