Before joining the police, May was a sergeant major in the Grenadier Guards.

Entity and relation annotations:
id: 0
type: entity
value: text: May
labels: <Person>
id: 1
type: entity
value: text: the Grenadier Guards
labels: <Organization>
id: 2
type: entity
value: text: sergeant major 
labels: <Title>
type: relation
to_id: 1
labels: Person:affiliated_with:Organization
from_id: 0
type: relation
to_id: 2
labels: Organization:Establishes:Title
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type: relation
to_id: 2
labels: Person:holds_title:Title
from_id: 0