LAKELAND — The Lakeland city commissioner who was charged last week with second-degree murder in the death of a would-be shoplifter has resigned from his elected position. A letter of resignation dated Oct. 20, the same day Michael Dunn was arrested, was hand delivered to Lakeland City Hall on Monday afternoon. "It is with a heavy heart that I submit this letter to you," Dunn wrote to his fellow commissioners and the city’s mayor. "Being born and raised in Lakeland, this city means a great deal to me and always will. Thank you to the residents of Lakeland for having given me the opportunity to serve." Dunn, 47, remained jailed Monday without bail. Polk County State Attorney Brian Haas announced Friday that Dunn would be charged with second-degree murder in the Oct. 3 shooting of Christobal Lopez. Related: Lakeland commissioner charged with murder in the shooting of suspected shoplifter Related: YouTube video shows commissioner’s arrival to the Polk County Jail Dunn had spotted Lopez pocketing a hatchet inside the Vets Army Navy Surplus store, which the commissioner co-owns. When police showed up, they found Dunn with his gun still pointed at Lopez, who lay on pavement near the entrance. "I think he expired," Dunn said, according to a criminal complaint. Dunn’s attorney, Rusty Franklin, filed a request Friday to dismiss the criminal charge under Florida’s stand your ground self-defense law. Franklin argued that Lopez, when confronted, threatened Dunn with the hatchet, putting the commissioner in fear. He called the killing justifiable. Haas, the state attorney, concluded otherwise. "It is the policy of my office to comply with and abide by the stand your ground law," he said Friday. "However, I have determined that this case and the actions of Mr. Dunn fall outside the protection of the stand your ground law." Police reviewed store surveillance video and interviewed two witnesses, including Lopez’s father. The video showed Lopez removing a hatchet from a rack and tucking it in his pants. Dunn, from an office, saw him do it. Related: Surveillance video shows Lakeland city commissioner shooting alleged shoplifter A few minutes later, Lopez’s father went to the front counter and paid for a "boonie" hat. The pair then moved to leave. Dunn confronted Lopez near the door, asking if he was going to pay for the item. The hatchet slid down Lopez’s leg to the floor. "I will pay! I will pay!" he said, according to the complaint. Lopez picked up the hatchet and went to the counter but tried to leave again without paying. Video shows Dunn holding a gun in his right hand as Lopez moves toward the door. Dunn pushes Lopez with his left arm. Lopez is seen gripping the door, trying to pull away, police said. He held the hatchet in his right hand, the blade against his palm Related: Did Lakeland commissioner need to kill suspected shoplifter? Investigation under way Dunn fired twice. Bullets hit Lopez in his upper body and his back, police said. Dunn made no effort to render first-aid. Police said Lopez made no threatening movements and witnesses heard no threats. Detectives asked Dunn what would have happened if he had let go of Lopez. He replied: "It might be fair to say that if I just stepped back and let somebody come in and take what they want, that there would be no issue." Lopez and his father had recently become homeless, the detectives noted. They previously lived in the rural community of Wauchula, in Hardee County. Both had been accepted into Lighthouse Ministries, a faith-based shelter program Contact Dan Sullivan at [email protected] or (813) 226-3386. Follow @TimesDan.