Binh Thai Luc, 35, has been arrested on suspicion of five counts of murder, police said in a press conference early Sunday evening. The victims still have not been identified and police have not been able to determine an exact cause of death, or offer a motive for the slayings. Investigators said on Sunday that the victims had clearly suffered "blunt trauma." The deaths were discovered at 7:45 a.m. Friday, when a relative of several of the victims walked into the home at 16 Howth St. and found a body in the entryway. She found two more bodies in the garage before running out of the house and calling for help. Police found two more bodies in the back of the home. Investigators had initially thought that the deaths might be a murder-suicide, but they quickly reported that the scene was too bloody and confused to be sure. The slayings were so gruesome that investigators have struggled to identify the victims or say how they were killed. Police emphasized on Sunday that the victims were targeted, and the slayings were not the work of a random killer. The house is located in a quiet Ingleside neighborhood near City College. Neighbors have said they were stunned by the killings in their normally crime-free community. San Francisco Chronicle