Nothing comes to mind off hand. I'd suggest harvesting spells from other systems. I'll note you some PDFs.

hehe thank you for the lists :3

Taking from the perceived paladin/cleric lists can be potent. If you can find a .pdf DND copy the book of vile darkness and the Book of the dead (Libre Mortis) might have lots of things. Flipping through black, especially B/W mtg cards can generate ideas. Along with oldhammer spell lists.

Spells the effect the mind: Mind control, forgetting things, gaslighting and thinking things, effecting what is read or perceived, especially wrapping sense of law or what is good.

Polymorphs fitting of punishment and not in the typical chaotic way.

Spells that force exchange and deals. An expectation to get something or be owed something in price. These are very lawful.

Death Knell is an older cleric spell that is down right useful and would be something in a lawful evil book as an act of mercy.

Spells that sacrifice servants/familiars for the good of the law or status co.

Spells that use the undead physical or spiritual for lawful means. Not in the normal necromancy means, but the eternity of service to "dark law" kind of means.

Spells that use as resource something to keep things lawful and thematic.