Sacramento County sheriff's detectives are investigating two sexual assaults that happened in the same area of Sacramento in less than 10 days.The first assault happened about 8:40 a.m. on Sept. 19 as a 15-year-old was walking to school in the 2200 block of Wyda Way.A man walked up to the girl, began talking to her and asked her age. The man then grabbed her and sexually assaulted her before she hit the man and ran away, according to the sheriff's department.The most recent attack happened about noon Tuesday as a 21-year-old woman was walking on Wyda Way with her two young siblings.A man walked up to the woman from behind and began talking to her. He then sexually assaulted her over her clothes and ran away, deputies said.The man's description and the area where assaults happen are very similar, leading detectives to believe that it may be the same person committing the crimes.Investigators worry the man is likely to try again."Our concern obviously is that he'll do more the next time," Sacramento County sheriff's spokesperson Tony Turnbull said. "He's testing the waters to see how much he can get away with."The man involved in Tuesday's attack was described as 24 to 34 years old, about 5 feet 8 inches tall, with a skinny build. He was wearing black pants, a black T-shirt and black doo-rag on his head.Anyone with information is asked to call the Sacramento County Sheriff's Department at 916-874-5115.