Student loan forgiveness police officer

Hey guys. So I just stumbled upon this sub and was curious if anyone would be able to direct me to any past posts regarding loan forgiveness for police officers. I've been a cop in Massachusetts for 5 years and was curious to know how people went about doing it, where they went to do it and if it was difficult to do. Also if they retro any of the benefits if you've been paying on time since you've been on the job. Any help would be greatly appreciated. Thanks in advance