Let us rehash this old chestnut.
How do you run Detect Evil in your campaign? Does it only detect innate evil? Can it ever be mistaken? Is it used as a justification for slapping some sod in the head?
Are people on the ball about having a spell cast on them, and consider it an invasion of privacy?
I never liked the idea that a pretty low level spell could divine someone's nature, and potentially short circuit a mystery. The Ravenloft setting just threw up their hands and said 'It don't work! Stop that!" Even so, if it does work, is someone justified in killing someone because a magic spell caused a red buzzer to sound off over their heads? Or merely imprisoning them because they're generically "evil"? Does any kind of due process enter the picture? What's to stop a cleric from saying that they detected evil in order to get at someone they don't like?
In looking up how 5th edition does it, I note the latest version only detects supernatural evil. That's a bit more my style.
Not in terms of D&D by my own system, this is how I use Detect Evil.
I start with the source of said evil, which can be 'vengeful thoughts/intents', ' degenerate/sinful thinking', possessed objects and lingering auras. Each of these is assigned a number based on how difficult it is to detect, that being 3/4/5/5 of 6.
From there, each of these things has a success threshold that, once met, will prompt the DM to inform the player 'direction', 'source', and 'cause', so the player can stop the attempt early if they just need to find a source.
As for how that threshold is met, my system uses a D6 dice pool system, and each 4 or 5 also counts as a success for the numbers below it.
Example: A PC has a pool of 5 dice between the two stats for the pool, and rolls a 2, 3, 3, 5, and a 6, with a 4 for the Exploding Dice on the 6.
That makes 5 successes at 3, 3 at 4, and 2 at 5. So, if there's someone in the area with some violent tendencies or form of degenerate thinking, this one roll would inform the PC of such and give them an idea of what direction they're in, but not the exact source or the cause of such thoughts.
Those thresholds can be increased however if there are a lot of people in the area, or if someone/thing is controlling the one giving off the evil presence.