A robber locked a 90-year-old woman in her bathroom before stealing money and bank cards from her home.
The thief struck at about 18:10 on Monday after gaining access to a common close in Milovaig Street in Summerston, Glasgow.
Police said he escaped with a three-figure sum.
The elderly woman was checked over by medical staff but did not suffer any injuries, although she was extremely shaken.
The suspect was described as being about 16 years old, 5ft 1in tall with a slim build and acne on both of his cheeks.
He was wearing a black woolly hat and a black tracksuit.
Det Insp John Morrison said: "This is a despicable crime carried out by a young man who clearly has no conscience and no regard for others.
"I am appealing to people in the area to think about the description and consider if they recognise it or know who the person is.
"Perhaps you noticed him in the area prior to the incident occurring or did you see him run off along Milovaig Street?
"Please, if you have any information or knowledge, get in touch and pass your information on."