MBTA Transit Police Sgt. Richard “Dic” Donohue is retiring from the department three years after he was shot and critically wounded while pursuing the Boston Marathon bombers, according to a statement issued today.

“Following my injury, I committed myself to returning to active service in the department. It took nearly two years to accomplish that goal, fighting through pain and limitations, but I had a lot of help from some amazing doctors, my family, and my fellow officers,” Donohue said in a statement. “I did not want it to be taken from me without a fight. Unfortunately, I must now acknowledge the extent of my injuries and limitations. Physically, I cannot perform at 100 percent and must do what is right for myself, my co-workers, and my department. Therefore, I will step away from the job that I love so much.”

Donohue was shot in Watertown on April 19, 2013 during an active police pursuit of Dzhokhar and Tamerlan Tsarnaev, who were responsible for the Boston Marathon bombings four days earlier.

Although Donohue’s injuries were severe — including nearly fatal blood loss — emergency responders rushed to his aid and saw that he was transported to Mt. Auburn Hospital, where doctors were able to save his life.

“I am forever grateful to my fellow first responders and the doctors who saved my life,” Donohue’s statement read. “There are too many to list, but they each have a special place in my heart.”

Donohue, 36, who lives north of Boston with his wife, Kim and 3-year-old son, Richie, recently accepted an adjunct professorship teaching criminal justice at a local college and is also an active ambassador and board member for the American Red Cross, according to the statement.

He and his wife are expecting another baby boy in April.

“I want to sincerely thank every person and organization that has been there for me since April 2013,” Donohue said. “There is not a day that goes by that I am not thankful for the support the entire community has shown me, my family, and my fellow police officers.”

Donohue stressed that while he would prefer to continue working as a police officer, his injuries, which left him with near constant pain in his legs, prevent him from being able to “fully discharge his duties as a police sergeant.”

“I am alive, and I have many plans for the future,” Donohue said. “If I had a choice, I would continue to serve as a police officer for decades to come, but those were not the cards I was dealt.”