According to our news partners at the St. Louis Post-Dispatch, the shooting occurred around 1 p.m. at the Lafayette Towne senior housing complex, located in the 1400 block of Ohio Avenue.
Homicide detectives said the suspect had complained the the assistant manager and another tenant were stealing money from his apartment. The elderly man was allegedly in the office with the assistant manager when he shot the victim in the chest. The man also fired shots at the tenant he accused of taking money, but missed.
Investigators said the suspect uses a motorized scooter to get around but can walk.
The suspect, who's name has not been released pending formal charges, is a convicted felon and should not have been in possession of a firearm. The elderly man was tied to three murders in 1973 and was released for those killings in 2003.
The victim has not been identified.
It's unclear if the assistant manager was responsible for stealing the suspect's money.