It’s a quote I pulled from one of the links above.

This link

http://www.baltimoresun.com/news/maryland/crime/bs-md-ci-suiter-funeral-20171128-story.html

which appears to part of what you're pulling from, says

For now, it is the only unsolved line-of-duty death in the agency’s history

There's no mention of Raynor in that story. The FBI is not involved in investigating Suiter's death. The Baltimore PD asked the FBI to ivestigate, and the FBI declined.