Investigators believe that 26-year-old Anthony Gardner knew someone in the home where he was killed.
Gardner was shot and killed in the 300 block of Albany Street early Saturday morning.
No arrest have been made in the case.
Police say Gardner lived in Des Moines but had acquaintances and possibly a girlfriend in Waterloo.
Investigators do not think the slaying was a random act.
The investigation caused a city block and some nearby railroad tracks to be cordoned off for much of the day Saturday.
If you have any information, call police or the Cedar Valley Crime Stoppers at 1-855-300-TIPS.