Not for the first time, scandal brings change in the Baltimore Mayor’s Office of Technology. After being put on paid leave in March and following a months-long investigation, Chief Information Officer Chris Tonjes resigned on Monday. Amidst allegations that his department paid contractors for work they had not completed, Tonjes denied any wrongdoing in a letter of resignation. "Having been arbitrarily placed on administrative leave amid a cloud of scrutiny, I have been unable to do my job and serve the citizens of Baltimore," Tonjes said in a letter to Mayor Stephanie Rawlings-Blake. "Neither my career accomplishments, nor my unblemished record of public service, nor the undisputed fact that I have not engaged in any wrongdoing have brought this never-ending investigation to a close."Tonjes (pictured at left) being placed on leave was cited as a routine step that did not indicate any wrongdoing on his part, according to city officials. Deputy Chief Technology Officer Jerome Mullen has been serving as acting chief for the past three weeks. The mayor accepted Tonjes’ resignation and praised Mullen for his ability to fill in for Tonjes. Tonjes was originally hired as a replacement to Rico Singleton, who was dismissed in Feb. 2012 following an audit revealing possible ethics violations. The city comptroller said emails showed that Singleton pursued a job with antivirus software provider McAfee for himself and his live-in girlfriend as he negotiated a contract with the vendor that was finalized in 2009. The audit also revealed Singleton had accepted improper travel benefits from McAfee on more than one occasion and that $1.5 million had been wasted on the McAfee contract when the state was unable to recoup enough licensing fees from agencies through the contracted service, which consolidated antivirus and security products for state agencies. Tonjes joined the Baltimore technology agency in late 2012, following his service as CIO for the District of Columbia Public Library, where he oversaw the creation of the library's first mobile application, broadband expansion for library branches, and an initiative to offer computer education classes to low-income residents. Tonjes told Government Technology he planned to help close the digital divide in Baltimore, expand the city’s fiber network, secure and enhance the city’s 800 MHz radio system, and improve 911 and 311 services. When asked in Jan. 2013 about his agency’s checkered past, Tonjes said he preferred to stay focused on his department’s goals. “What I'm trying to do is focusing on delivery, focusing on my priorities, trying to keep my commitments to people so that whatever missteps or things that have happened in the past are no longer yardsticks that people use to judge my agency,” he said. Tonjes said in his letter that the decision to leave his position was difficult since several of his projects are near completion, including a Wi-Fi installation at the Inner Harbor and a new billing system for water meters.