A discarded hypodermic syringe appears to be at the center of an assault at a Petaluma homeless encampment. On Monday at the Cedar Grove Parkway encampment, the victim says that 29-year-old Brian Guiliani got into an argument with him over the victim leaving a syringe near Guiliani’s camp. Guiliani was upset as he had his 3-year-old child in the encampment at the time. The next day, while the victim was helping a friend string a guitar, Guiliani struck him with a wooden baton three times and stole $10. Police responded and arrested Guiliani, who denied his involvement, but had methamphetamine and $10 when apprehended. The victim was treated at the camp by paramedics.