Ezekiel Chepkowny said today that Gallman was patrolling the ranch when she was attacked and shot in the stomach.
Chepkowny says her driver also survived the attack and drove her to the airport in Laikipia, where she was airlifted to the capital, Nairobi, for further treatment.
Richard Constant, the deputy chairman of the Laikipia Farmer Association, says suspicion falls on herders from the Pokot community who have invaded Gallman's ranch several times.