Answer: cooperative

AnswerCrossword Clue
COOPERATIVEWilling to help
COOPERATIVELike a good police witness
COOPERATIVEAccommodating
cooperativeworking together / an enterprise or organization owned by and operated for the benefit of those using its services
cooperativeInvolving mutual assistance in working toward a common goal
cooperative(of a farm, business, etc.) Owned and run jointly by its members, with profits or benefits shared among them
cooperativeWilling to be of assistance