LITTLE ROCK, Ark. - As an officer with the Arkansas Highway Police Department was signing off for the last time before retiring, he got a surprise from his son. 

After 31 years of service, Cpl. Roy Martin retired Tuesday. According to a post on social media, his son Cprl. Billy Martin was given the opportunity to give his father his last 10-7 call on the radio. The department said said Roy had no idea his son would be on the other end of the radio.

 Be sure to watch the emotional video.