He breaks in through windows late at night and early in the morning, and in some cases, his victims have been at home.
"We're concerned because it has been escalating. During these last summer months it has gotten to the point where this guy is getting really bold. He is not really shy about what he is after. That is why we are concerned, especially if a female is home by herself or with her children -- that is an obvious concern that we want to address," said Officer Anthony Ortiz, Ontario Police Department.
It's not just underwear the bandit wants either. He's also taken a small amount of jewelry.
Anyone with information is urged to call the Ontario Police Department at (909) 395-2001.