Identify Vitals

1st-Level Enchantment (Ritual)
Casting Time: 1 action
Range: 60 feet
Components: VM($) (a small crystal lens set in a gold frame worth at least 50 gp)
Duration: (C) 1 minute

Target a creature within range that you can see. You gain knowledge of any damage vulnerabilities they may have, and for the duration of the spell, your vision is augmented to allow you to see that creature's internal anatomy, allowing you to strike with greater precision and deadliness. Before the spell ends, you have advantage on weapon attacks and medicine checks against that creature, and you can also score a critical hit on that creature with a roll of 19 or 20.
If you target a dead creature with this spell, you also gain the benefits of a successful Appraisal check on that creature. The benefit of this Appraisal check is not lost after the duration of this spell.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, you can target one additional creature for each slot level above 1st. The creatures must be within 60 feet of each other when you target them.

Source: Hamund's Harvesting Handbook: Volume 2