The suspects in two separate crimes — a carjacking and a mugging — ended up in police custody this weekend, after trackers in their victims' cell phones led police straight to them.

It was 5 p.m. on Friday when the first abortive crime went down: A 53-year-old man was seated in a parked 2015 Toyota Prius at the intersection of John F Kennedy Drive and the Great Highway, at the end of Golden Gate Park, when a 25-year-old woman approached the vehicle "and demanded his keys," according to the San Francisco Police department.

When he refused, the woman "brandished a firearm," police say. Faced with the gun, the victim handed over the keys to the car, and the weapon-wielding woman fled in his vehicle.

However, the victim had left his cell phone in the car, which ends up being good news instead of bad, as the device had an active cell phone tracking program (like Google's Android Device Manager, Samsung's Find My Mobile, Apple's Find My iPhone, etc). Because of that, police say, officers were able to follow the phone, find the car, arrest the suspect, and reunite the victim with his Prius and phone.

In the second case of alleged phone tracker justice, an 18-year-old skateboarding on the first block of Ellington Avenue was pushed off his board by two men at 11:35 p.m. Sunday.

The duo, who were aged 19 and 20, took the victim's cell phone and wallet, then fled on foot. But since the phone had a tracker enabled, officer were able to track the phone, locate the suspects, and detain them for the alleged crime.

Previously: Phone Tracker Leads SFPD To Teenage Mugging Team