One victim of an "office creeper," who didn't want to be identified, said it happened fast.
"People like her, like these office creepers, they need to be stopped," she said.
The victim said she was in a meeting in her downtown Dallas office building when someone stole her wallet out of her purse on her desk.
"Unfortunately, the things she stole from me are things that never expire until I die, so I will have to be looking over my shoulder for the rest of my life," she said.
Dallas police said the office creepers are striking nearly every day in downtown, so they're distributing a list of the top 13 offenders in the Central Business District.
"The important thing is to be on the look out for anyone who's not supposed to be in your employment or business," Dallas police Lt. Andrew Harvey said.
The so-called creepers aren't isolated to bustling downtown areas.
On Monday, two teenagers were arrested on suspicion of posing as high school students and stealing from a locker room at Colleyville Heritage High School.