An arrest warrant has been issued for Sau Van Le, a 14-year-old Garden Grove boy suspected of shooting and killing a Vietnamese mother of 14 last month as the woman knelt in prayer, Santa Ana police said. Huyen Thi Hoang, 46, was killed during what authorities said was a failed robbery attempt while her husband and 12 of her children were in other parts of their home. Officers encouraged the Vietnamese community to continue its efforts to locate Sau and said the arrests of four other suspects would have been impossible without refugee assistance. Tien Van Nguyen, 20, was arrested on suspicion of murder June 12 as he left his Garden Grove residence, authorities said. He was charged with murder, robbery and burglary. Three other juvenile suspects are in custody and face the same charges.