… the police do not state it was found on the bench. “Sorry not found on the bench…” which implies it was found elsewhere.
Fingerprints on the phone may be able to confirm if someone held it / picked it up and put it on the bench, unless they had gloves on of course. Fingerprints also will confirm if the business owner picked it up (the screen was locked according to one report) unless there were gloves and of course also if police have treated the phone as evidence and recovered them all from the device to see who exactly has handled that phone and to corroborate what they know from whatever witnesses they have as to the device …