The mother of a teenager killed by her police officer boyfriend last year is filing a lawsuit against the NYPD.

Shirley Fontanez was shot to death last July by Officer Fred Maselli, her 40-year-old boyfriend. Maselli then turned the gun on himself and committed suicide. Fontanez was only 18 years old at the time of her death.

Maria Espinoza, Fontanez's mother, says the NYPD ignored several abuse complaints involving Maselli. She hopes taking the department to court will help bring some sort of closure to the tragic event.

Espinoza says even if she does win her lawsuit, she will carry the greatest loss with her for the rest of her life.

BX cop, girlfriend dead in possible murder-suicide