A man shot and killed four members of his family before turning the gun on himself inside their south-side home, Tucson police said.

Police on Wednesday identified the shooter as Christopher Carrillo, 25.

His four victims were identified as 58-year-old Raúl Carrillo, 53-year-old Karen Saari, 32-year-old Erick Carrillo, and 17-year-old Isela Rodriguez, according to a Tucson Police Department news release.

Erick and Christopher were Raúl and Karen's sons, and Isela was their grandaughter, police said. Neighbors said they were longtime residents of the neighborhood.

Saari is listed in Pima County property records as the owner of the home. A friend said Saari worked for many years for the state's Adult Protective Services.

Police confirmed Wednesday afternoon that the incident was a murder-suicide.

Tucson Police Chief Roberto Villaseñor, who was at the scene Tuesday night, gave the following account:

911 was called shortly before 6 p.m. by a man who went to the house to meet with an acquaintance, looked inside and saw a person with obvious signs of trauma.

When police arrived they found the five people, males and females, dead with gunshot wounds in various roooms of the single-story house, which is in the 800 block of West Calle Medina.

All five appear to have died sometime Tuesday, Villaseñor said. 

The neighborhood is south of West Valencia Road and west of South 12th Avenue at South Santa Clara Avenue.

Police would not comment on any guns found in the home.

Officers have been called to that home before, but details weren't immediately available.

Neighbors were stunned by the incident at the home of a family that had lived in the house for more than 20 years.

They said the family kept to themselves, but would say hello in passing. Raúl Carrillo, who everybody knew as "Rudy," liked to walk around the neighborhood in the morning. He could often be seen cleaning up trash on the street near his home. He also volunteered at a nearby church.

Araceli Zatarain, who was stunned by the deaths, said she didn't hear any noises from the house on Tuesday and didn't know something was wrong until a police officer came to her door, telling her that she needed to leave.

Officers were outside the Carrillo house and were yelling for Christopher to come outside, Zatarain said. She said she heard no gunshots.

Friends of Isela Rodriguez stopped by the home Wednesday afternoon to place candles near the front gate.

The house is surrounded by a block wall and has "No trespassing" and "Beware of the dog" signs posted. The girls, who declined to be identified, said Isela was a student at the nearby Southgate Academy. She apparently didn't live at the house but may have been visiting when the shootings happened.

Tiana Sloan said Isela was very friendly and made new students at the school feel welcome.

Sylvia Calmelat, superintendent of the school, said Isela dropped out of the academy in March and was attending another school.

She said some of the students were affected by the "horrible tragedy" and counselors spoke to them Wednesday, and counselors were available if needed.

Another neighbor said he saw Raúl and Erick Carrillo on Monday outside the home when he helped them change a flat tire on a car. He said that they drove off and that was the last time he saw them.

Contact reporter Carmen Duarte at cduarte@tucson.com