Police were called Modbury Hospital around 5.30pm over reports that a man had assaulted two men, including a 90-year-old in the hospital’s car park before stealing their wallets.
He also stole a woman’s handbag before walking away, police will allege.
A security guard was also allegedly assaulted after he attempted to confront the man.
The 90-year-old man suffered injuries to his face, and was treated at the hospital.
His injuries were not considered life-threatening.
Both other men also received treatment.
Police patrols including the dog squad began looking for the alleged offender, who was later located at a home in Ridgehaven.
The 36-year-old man was arrested and charged with two counts of robbery, two counts of assault causing harm, theft and assault.Â
He was refused bail and will appear in the Adelaide Magistrates Court today.
Police have asked anyone who witnessed the assault to come forward.