Woman says niece's murder, sister's brutal attack led to arrest of alleged serial killer in Mexico

SANTA ANA, Calif. -- An American woman is in shock and mourning after her niece was killed and her sister was brutally attacked by an alleged serial killer in Mexico who targets women.

Angela Calles is from Santa Ana, California. She says her sister, Cassandra Calles, and 17-year-old niece, Maria Jose Castillo, were both victims of the suspected serial killer.

"Right now my niece is supposed to be studying for going to school. She's supposed to be with her mom and right now she's not at home. She's in a place where all the bodies go when they're killed," Angela said in tears.

Police in the Mexican city of Iztacalco said the teenager was brutally raped and murdered on April 16 by her neighbor, 39-year-old Miguel Cortez, a pharmaceutical chemist.

Angela said she spoke with her sister, the teen's mom, in the ICU. Cassandra told Angela she returned from a trip to the corner store and found Cortez hovering over her daughter's body.

Cassandra told her sister she fought for their lives, but Maria was already gone.

"He tried to push her down the window. So then she grabbed herself from the curtains on the same room and then he threw her back again into the bed," Angela relayed.

Angela said she was told that the suspect then ran off to his apartment on the third floor and that her sister woke up covered in blood from several stab wounds but was able to walk downstairs and let police in the building.

Cell phone video shows angry neighbors as police arrested Cortez.

This uncovered a nightmare investigators said dates back to at least 2012.

According to city prosecutor Ulises Lara, evidence discovered in Cortez's apartment included skulls, other human remains, a saw, the identifications of several women and notebooks filled with gruesome details.

Cortez was accused of femicide and attempted femicide. Police said he murdered six women and attempted to kill a seventh.

Investigators said among his victims was Frida Sofia Lima, a former girlfriend of the suspect who went missing in 2015.

Angela said she was angry upon learning Cortez's alleged killing spree lasted more than a decade.

"If they have been doing something years before and stop this killer, maybe my niece is still alive," Angela said.

Angela called her sister a hero whose fight to save her daughter may bring justice to many families. She hopes to see Cortez spend the rest of his life behind bars so her niece's death is not in vain.

"She was a very, very smart kid. She was lovely with her mother. She and her mother were very like that bond of mother and daughter, you know," Angela said.

The family started a GoFundMe to cover expenses for the legal battle for justice. Angela said she will pressure prosecutors in Mexico to ensure Cortez dies in prison.

The family said they were waiting for Cassandra to recover to bury Maria.

According to Angela, the suspect is due back in court in six months.