The Assassination of Morty Bennett was a measure planned by William Rawlins and executed by Billy Russo in order to silence Colonel Morty Bennett, who had become a liability once Frank Castle learnt of his involvement in Operation Cerberus.
Frank Castle and David Lieberman organized infiltration into the Fort Bryon where Colonel Morty Bennett was stationed. Castle successfully got to Bennett and threatened him while Micro downloaded tracker at Bennett's phone. William Rawlins and Billy Russo knew about it and organized ambush on him. However, download of tracker was completed and Castle escaped. Russo brought Bennett away from danger to safehouse and he listened to Bennett yell at Rawlins as he then furiously blamed him for allowing the Punisher to ambush and almost kill him.
The trio discussed what was disclosed and relocating the colonel with a new identity and a safe house to keep him away from Castle's sights. Although Bennett acknowledged that Rawlins had clearly set him up, he agreed to begin the new identity using all of the money Rawlins had made for him and begin a new life, safe from Castle's rage, with Russo agreeing to handle all of the details to ensure Bennett's safety. Actually, Rawlins and Russo decided to kill Bennett.
Having left all of his personal possessions and his phone behind, Bennett followed Billy Russo to the cheap motel. As Bennett explored the room, he found his Mistress lying dead on the bed with her throat slit. As Bennett recoiled in horror, he turned around to Russo who was calmly getting up and walking towards him as the desperate Bennett tried to take back all of the insults had given Russo.
Russo, however, ignored Bennett's pleas and managed to disarm Bennett when he tried to draw his gun, before plunging his hidden blade into Bennett's gut, fatally wounding him. With Russo following the orders of William Rawlins, he cleaned his blade and watched as Bennett desperately tried to crawl to safety, with Russo telling Bennett that he had never liked him much either. Despite attempting to get away from his attacker and failing to get to the phone to call for help, Bennett eventually lost too much blood and died on the floor, with Russo leaving his bloodied corpse behind.