Lexuary watch solved murder

If you are looking for the real story that inspired this trope, look no further than the Albert Walker case (1996).
​A fisherman found a body in the English Channel with no identification except for a Rolex Oyster Perpetual. Because Rolex keeps meticulous service records, police used the serial number to identify the victim as Ronald Platt. Furthermore, because the Rolex was waterproof and had a specific power reserve, forensic experts were able to determine the date of death based on how long the watch continued to tick after being submerged.
​"A luxury watch doesn't just tell the time; it tells the truth."