Dead Weight - S1-E4
Character mistake: When Columbo first comes to the general's apartment, the general is showing Columbo a submachinegun. He also shows him a magazine and says it is an "extra clip." A retired general would know the difference between a clip and a magazine; the terms are not interchangeable.
Answer: "Apparent" drowning answers your question - things are not always as they seem. Drowning could be accidental, but it could also be a murder in disguise. Moreover, the actual cause of death has not yet been determined - accident, suicide, murder, or natural cause (e.g, heart attack while swimming). Columbo would be there to investigate if anything looks unusual for it to be a mere drowning or if there is evidence or suspicion of something else.
KeyZOid
This was just on TMZ.com's "Aaron Carter Dead at 34" (11/05/2022): "Law enforcement sources tell TMZ... homicide detectives have been dispatched to the scene but we have no information or evidence of foul play. It's standard operating procedure for homicide detectives to investigate such [drowning] death scenes."
KeyZOid