From the article: "Montesi, 29, said he was speeding to catch up with other deputies when he swerved his vehicle on Jan. 11 to avoid hitting Josiah's friend, who was walking his bike across the road, but he ended up hitting Josiah, who was walking behind him."
and
"Hillsborough Sheriff Chad Chronister placed the officer on a five-day suspension, without pay, for Sheriff's Office Standard Operating Procedure for speeding even though he wasn't involved in an emergency operation."
This wasn't even a high-speed chase, he was just trying to catch up to his buddies. If vehicular homicide doesn't fit (since apparently speed isn't the only factor), then negligent homicide should.
“he was just trying to catch up to his buddies.”
Sounds like he was on a 10-199.