Los Angeles police said they were on 3rd and Alvarado streets investigating a robbery Sunday night when they discovered the kidnapping also took place.
Witnesses told investigators that they spotted a man beating up a woman outside the Holiday Lodge Motel on W. 3rd Street before he allegedly took her to a car.
Authorities found the woman inside a car nearby, and she was taken to a nearby hospital with unspecified injuries.
Police said the suspect, believed to be behind both crimes, was later arrested at an apartment complex in the area.
The suspect's identity was not released.