Medical Examiner Dr. Qin: Bones of the Past

Fifteen years ago, a young girl was kidnapped on the way from school, and Park Hae Yeong, who was an elementary school student at that time, witnessed the crime. A few days later, the girl was found dead, and the police were not able to find the culprit. As time went by, Hae Yeong started distrusting the police. Fifteen years later, Hae Yeong is now a police officer and criminal profiler. One day, he finds a walkie-talkie that allows him to get in contact with Detective Lee Jae Han who is in the past. Police officers Hae Yeong, Jae Han, and Cha Soo Hyun then set out on a journey to solve cold cases.

ML is able to connect with his missing father via old cell phone. Both were police detectives and work to solve cases, and figure out what happened to his father.

Same character and ML actor, different cases and plot. Both are mini dramas within the same universe.

Both are short length dramas in which the current day police officer ML is trying to solve a mysterious murder case involving the skeleton of a woman and finds his phone/walkie-talkie connects to the past and a police officer working on the same case. The two then join forces across time to try to solve and prevent the events from happening.