Ross Mitchell, 38, of Hilltown Court, had sentence deferred for reports.
Mitchell admitted that he forced open a car and stole a mobile telephone at Hindmarsh Avenue on November 5.
He also admitted forcing open a lockfast car in Isla Street and stealing a quantity of tobacco, and being in possession of heroin at police headquarters in Bell Street, also on the same date.
The court heard that a passing taxi driver spotted Mitchell leaning into a car and removing items from it through a smashed rear passenger window.
When police arrived, the accused was seen running into a close and discarding a small hammer, called a window breaker, which was recovered.
Mitchell was searched and found with heroin.
Sentence was deferred until December 4.