[Chewbarkah]

Are these photos the mugshots they appear to be?
Concord, Mass, June ‘68, and the number 40058 are self-explanatory, but what does “C.I.” mean in this context? The 6d finishing nail-looking artifact above his ear is also curious.

Was he a Confidential Informant? Criminal Investigation? The articles sure don’t tell us much about his criminal history BEFORE the 1969 crime.

[ETL]

Sorry, can't answer your questions.

But here's a little additional info...

[ETL]

Here is the source for that last pic.

excerpt...

“In October 2012, the Suffolk County District Attorney’s Office identified Sumpter as the assailant in the Dec. 12, 1973 homicide and sexual assault of 24-year-old Mary Lee McClain at her Beacon Hill apartment in Boston.

Ivanka Trump Used Personal Email for Government Work: Report

At that time, McClain’s death had been the second attributed to Sumpter through DNA testing. Two years earlier, authorities linked him to the 1972 rape and murder of 23-year-old Ellen Rutchick at her Beacon Street resident in West Roxbury.

Prosecutors say they don’t believe Sumpter knew any of his victims.”

https://www.nbcwashington.com/news/national-international/Middlesex-District-Attorneys-Office-to-Reveal-New-Development-in-1969-Cambridge-Cold-Case-500925461.html

[ETL]

what does “C.I.” mean in this context?

Probably...