The Wizard of Santa Fe

The Wizard of Santa Fe - Simon Hawke In the 23rd century, after something referred to only as the Collapse, magic has made a comeback.
In Santa Fe, bodies are turning up with strange symbols carved into them, and the local police gets helps from the resident mage.

Into the investigation come Merlin (in the body of one of his ancestors), Kira & Wyrdrune, both with magical runestones embedded in them from an earlier adventure.

To mess things up further, the Bureau of Thaumaturgy burst in trying to cover themselves in glory by taking down the murder cult they believe is behind everything.

This is part of a series (which explains the background of Merlin et al) but reads well as a standalone story, concentrating on the locals. There are plenty of interesting characters, from a sentient broom, various computers, and magically enhanced animals as well as the humans.