90 day mandatory sentence for having heroin track marks?

I was reading Scar Tissue by Anthony Keidis, and in it he writes that he was once arrested mistakenly (he fit the physical description of a bank robber) and detained overnight. He claims that you got a 90 day mandatory sentence for having heroin track marks, and that he was able to talk his way out of it but was told that he’d have to cover up and hide it from the other officers.

What? I didn’t know they did stuff like that. I thought that if you weren’t in possession of drugs and weren’t under the influence of them, you couldn’t get in trouble. I know next to nothing about the laws relating to drugs, so maybe I’m wrong. What’s the deal with this law? Is it still on the books?

I don’t have any direct knowledge of whether it’s a law or not but it seems dubious.

Track marks are small marks around the areas of the body where veins are. For sake of argument we’ll say the arm. Small marks are indicative of not very much. Could be heroin use. Could be use of another drug. Could be a legal drug. Could be from use in another country where drug x is legal. Could be from self-harm. Could be from an attempt to look cool. Could be from some sort of abuse. Could be flea bites. I could go on all day thinking up wackier and wackier reasons to have small marks on the arm. Many plausible.

I’d also query what evidence the police would be able to find for heroin use based on marks alone. Surely they’d need to do a drug test otherwise there could not be a case based on drug use. It would be a bit like prosecuting somebody for having the syringe that comes with the first aid kit.

Track marks don’t really look like flea bites or a skin rash, but anyone who has needed IVs or frequent blood tests (say a recent stay of more than a week in hospital) is going to have “track marks” and collapsed veins.
Doesn’t seem right- more like a way for the cop to get bribes (assuming Kiedis “convinced” him with more than words).

No Google hits for “track marks” “90 day” mandatory.