Studies of homicide offenders that engage in repeat, non-serial homicide offending are scarce and most studies lack comprehensive criminal career data that include convictions for 1st degree murder. Drawing on archival data on 682 male convicted felons from the Florida Department of Corrections, the current study examined the prognostic association between prior 1st degree murder convictions and various specifications of subsequent homicide offending. Negative binomial and logistic regression models found that prior 1st degree murder convictions were significantly associated with current/instant homicide offending and multiple homicide offending despite controls for five forms of serious felony violence, age, and race. Suggestions for future research are proffered regarding the forensic and criminological value of 1st degree murder convictions.