MILWAUKEE -

Authorities said a Milwaukee man stabbed his girlfriend 16 times in a killing that has drawn attention because it took police nearly 22 minutes to respond.

Fifty-two-year-old Moreal Wilson was charged Friday with first-degree intentional homicide in Tuesday's death of 60-year-old Barbara Killebrew. When he turned himself in to police, he said he'd stabbed her in the chest during a scuffle.

While a fire engine arrived within three minutes of the 911 call, personnel waited to treat Killebrew until police arrived to secure the scene.

The Milwaukee Police Department said it's conducting an internal investigation into the delay.

Online count records don't list an attorney for Wilson, who was sentenced to 18 months in prison in a 2010 domestic battery case in Kenosha County.