Arkansas is a one-party consent state (Ark. Code § 5-60-120).
"Private" = reasonable expectation of privacy (e.g., inside a home, private office). "Public" = no reasonable expectation (street, park, loud restaurant).
Illegal recording is a Class A misdemeanor (up to 1 year jail, $2,500 fine). Civil liability also possible.
When in doubt, announce recording. For legal proceedings, consult an attorney on admissibility.