Bartolomeo Gagliano was born in 1958 in Italy. His early life was troubled—he suffered from mental illness, showed signs of severe instability, and was repeatedly institutionalized in psychiatric facilities. Gagliano spent most of his young adult life in and out of hospitals and jail cells. By the late 1970s, he had already been involved in violent and antisocial behavior. He was diagnosed with psychiatric disorders and spent significant time under state supervision in mental health institutions. Despite this, the system failed to prevent him from committing increasingly violent acts, eventually turning deadly. 

Gagliano's confirmed killing spree began on January 16, 1981, with the bludgeoning death of 22-year-old Paolina Fedi. He was convicted for this murder and sentenced to prison. After serving time, he was released but continued his violent behavior.

On February 8, 1989, Gagliano murdered 32-year-old Nahir Fernandez Rodriguez by shooting her in the mouth. Just days later, on February 14, 1989, he killed 34-year-old Francesco Panizzi in a similar manner. These brutal killings earned him the moniker "The Valentine's Day Monster."

Gagliano was apprehended and incarcerated for his crimes. However, on December 17, 2013, he was granted a temporary release from a Genoa prison to visit his mother. Instead of returning, he fled, prompting a nationwide manhunt. He was captured on December 20, 2013, in Menton, France, near the Italian border.

After his capture, Gagliano was held in a French prison before being extradited back to Italy in April 2014. On January 22, 2015, he was found dead in his cell, having committed suicide by hanging.