Why did Downey police officers shoot an unarmed man? That is what family members of 31-year-old Michael Lee Nida want to know.Nida was shot and killed by police Saturday after officers said he resembled a suspect in a nearby armed robbery. At about 7:15 p.m., as his wife pumped gas near Paramount Boulevard and Imperial Highway, Nida, according to reports, walked across the street to purchase cigarettes. That's when he was confronted by officers. Nida bolted, running into the yard of a nearby house. He was captured, but escaped again, leading officers on a foot pursuit. "(Downey police officers) said the individual was acting almost like a caged animal and that his actions were very aggressive and he believed he was armed and he believed he was a dangerous to everybody around him," Lt. Dave Dolson of the sheriff's department told KCAL9. As officers gave chase, Nido "turned toward the pursuing Downey officers in an aggressive manner," sheriff's officials said in a news release. "Fearing the suspect was armed, an officer fired at the suspect, striking him." Nida's mother, Jean Thaxton, told KTLA that her son was shot five times -- twice in the back, once in the shoulder, once in the wrist and once in the chest. He died at a local hospital. No weapon was recovered at the scene. There are conflicting reports of whether Nida was involved in the initial armed robbery. Investigators on Sunday initially said Nida was likely not involved, but backed away from those statements today, saying they could not confirm those reports. The results of the sheriff's investigation will be forwarded to the district attorney, which will determine if the shooting was justified. In the meantime, family members have established a fund to help pay for funeral expenses. Donations can be sent to the Michael Nida Memorial Fund, P.O. Box 3272, Huntington Beach, CA 92605. Nida is survived by a wife and four children.