Police said 14-year-old Aaliyah Johnson and her 56-year-old father Reuben Johnson were both found dead Saturday of gunshot wounds. The medical examiner's office revealed Aaliyah Johnson was shot in the head and her father was shot in the head and chest.Regina Renee Johnson is suspected of killing her husband and daughter, and police said she was discovered near the bodies in their condo. The family had rented a second-floor condominium at the Lomas del Cerro complex on Navajo Road, near Jackson Drive, for more than a year, police said."It's our belief that the victims were killed sometime Wednesday morning and the suspect remained in the (home) the entire time," San Diego police Lt. Kevin Rooney said.Regina Johnson had called a relative in another state and mentioned that her husband and daughter were dead. That relative reported the deaths, authorities said.A neighbor in the complex, who only wanted to be identified as Linda, told 10News she felt nervous around Reuben Johnson."He's very quiet. He wasn't really friendly; didn't seem to share or seem very happy," said Linda.Clinical psychologist Dr. Michael Mantell told 10News, "I don't think she went from a happy person one instant to suddenly losing her mind and pulling out a weapon and murdering her daughter and husband."Mantell said typically there is a sense of loss, failure, rage and depression that builds over time -- until there's a tipping point."I can't cope. Life is overwhelming and that snap can happen just like that," said Mantell.Aaliyah's friends told 10News that Regina Johnson "used to be so sweet."Mantell commented, "Believe it or not, there are mothers who think their children are better off dead; so they do this, 'out of love.'"Mantell offered this theory about the shootings: "The one shot to the head suggests that she knew exactly what she was doing and there was no second-guessing."Once the act was complete, though, Mantell said the fact that she stayed in the apartment for several days with the bodies suggests that she did have regrets."Psychosis, severe mental illness, a snap, guilt; a sense of feeling some second guessing, wanting to continue to be close," said Mantell.Reuben Johnson served in the Navy for 20 years, retiring in 2009 as a chief petty officer. He was working as a security guard, according to his sister, Deborah Spinner.There is no known motive, though court files show several liens and bankruptcy proceedings.