HIALEAH, Fla. -

"He was somebody who was not too willing to change," said Elmo Lugo, Pedro Vargas' former job supervisor at Miami-Dade College. "He was very introverted, couldn't really relate to a lot of the staff and was kind of in his own world."

On Friday night, Vargas, 42, set a combustible liquid on fire in his apartment, sending the unit into flames, police said. Building manager Italo Pisciotti and Samira Pisciotti, his wife, went running toward the smoke. Vargas opened his door and shot and killed both of them, Lt. Carl Zogby, a spokesman with the Hialeah Police Department said.

Special coverage: Hialeah massacre

Vargas then went back into his apartment and began firing from his balcony. One of the shots struck and killed Carlos Javier Gavilanes, 33, who neighbors said was returning home from his son's boxing practice.

Vargas then stormed into a third-story apartment, where he shot and killed a family of three: Patricio Simono, 64, Merly Niebles, 51, and Pricilla Perez, her 17-year-old daughter.

Vargas took the two hostages, before he was shot and killed by police.

Lugo said he saw the warning signs in Vargas' inappropriate behavior at work until Dec. 2008, when Vargas, a graphic designer, was forced to resign his position.

Vargas reportedly downloaded on his work computer at least 24 files deemed inappropriate.

"That's my head decapitated," Lugo said while showing Local 10's John Turchin a photo that Vargas allegedly sent him.

Lugo told Local 10 that Vargas continued to send threatening messages to his former boss, which Lugo reported to authorities, right up until Vargas' inexplicable actions turned violent and deadly.

"We're still trying to figure out, what caused him to act the way he did," said Hialeah Police Chief Sergio Velazquez. "It is not reflective upon the community that we have. This is a community that is united behind our victims."

On Tuesday night, a viewing for 33-year-old Carlos Gavilanes was held at Funeraria Memorial Plan San José, located at 250 E. 4th Avenue in Hialeah. The funeral Mass will be held at Immaculate Conception Catholic Church, 4497 W. 1st Avenue, at 11 a.m. Wednesday. The burial will follow at Miami Memorial Park, 6200 SW 77th Avenue in Miami.

PHOTOS: Victims of Hialeah fatal shooting ID'd

Published On: Jul 27 2013 04:25:58 PM EDT   Updated On: Jul 27 2013 11:59:39 PM EDT

A look at the seven people who will killed after a shooting and standoff at a Hialeah apartment complex.

Samira Pisciotti Italo Pisciotti
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Samira Pisciotti and Italo Pisciotti.

Vista Memorial Gardens & Funeral Home donated the burial for building manager Italo Pisciotti and Samira Pisciotti, his wife. A viewing will be held beginning at 6 p.m. Wednesday at 14200 NW 57th Avenue in Miami Lakes. Their burial service will begin at 9:30 a.m. Thursday.

Funeral arrangements were still being made for the other three victims.

Donations to the families of the victims can be made to: Survivors Pathway, PO Box 138882, Hialeah, FL 33013

Read: Cleaners enter gunman's apartment | Memorials grow for victims | Who was Pedro Vargas?