A gerontocracy... each city has a council of the oldest 21 citizens. The only ways off the council are death or depersonhood... Council members are required to record when 2 or more are present in the same room or outside on the same block; all those are available for review at any time.
By death, it can be deletion of personality or the self administration of lethal injection.
Depersonhood results in a brand and tattoo on the forehead, as well as tattoos on the eyelids. Further, a microchip is implanted. Non-persons get nutritious kibble, safe and adequate water, a capsule berth, and may do day labor; stable labor, engaging in contract, owning property, using public transit, participating in the annual review vote,
Once a year, the public are asked to vote on each council member, via ranked preference single transferable vote, between "continue," "deperson," or "death." Sentence will be carried out 10 days after the election...
The crimes that merit death, besides losing the election badly, include Premeditated murder; violent, drugged, or coercive sexual assault; slander, libel, or defamation of anyone not on the council; torture of a person or animal; abandoning one's governmental post, bribe receiving, or fraud when in public safety or medicine; flight to avoid prosecution.
Anything else is handled by Weregeld. (Life price is expected remaining lifespan at current wage; minimum is 10 years, and 10 hours/week at minimum wage for the unemployed. Anything else is by full cost of remediation.)
Trial is by high autonomous software judges.
Note that lethal injection is always the decision of the condemned; a phlebotomist places a veinous catheter, a pharmacist prepares an autoinjector with a 2×LD100 dose of IV poison; it's the condemned's choice of narcotic, neurotoxin, hemotoxin, paralytic, or an oxygenation inhibitor (IV suffocation!). They are given 24 hours to use the autoinjector; if they don't, they'll be sedated for brainwipe.
Brainwiped individuals either get a respected murdered person's recorded personality overlay, or get a simple overlay for manual labor - usually cleaning of public spaces; some are moved into the fire services as in-structure search and rescue specialists.
All brainwiped persons installed/trained personalities are aware they are in a wiped body - the manual laborers are also set not to care.