A 47-year-old man fatally beat his girlfriend Friday morning inside a house in Germantown, police said.

By the time officers arrived at the home about 10:40 a.m., the 24-year-old woman was already dead, police said. The boyfriend, whose name was not released, was taken into custody. The victim's name also was withheld.

A police spokeswoman said investigators believe the couple lived in the home, on the 4600 block of Greene Street.