A woman who stole money from elderly people in a Warwick nursing home was caught after police used covert forensic technology.
Last month police launched an investigation after concerns were raised money was being stolen from residents at the nursing home - which has not been named.
In a bid to catch the thief Warwickshire Police and West Mercia Police's We Don't Buy Crime team sprayed SmartWater on £10 and £20 notes.
The thief Rita Ampaw, 20, from Hinckley Road in Coventry was caught with the SmartWater cash traces of the chemical on her skin.
Superintendent Tom Harding, who leads the We Don't Buy Crime Team, said: "This is a prime example of some of the covert tactics we're deploying to catch people who abuse their position of trust and target vulnerable people.
"Protecting those who need our help the most is our absolute priority and it is shameful elderly people have been taken advantage of by someone who was there to look after them.
"Thieves who think they can get away with committing such despicable crimes can think again, anything they steal could be marked and they could ultimately be caught red handed."
Ampaw was was charged with theft from person and given a Community Order to run until January 2019 at Warwick Magistrates Court on Thursday, July 12.
She must also carry out unpaid work and pay court costs.
SmartWater is a forensic traceable liquid provided by Telford based company, SmartWater Technology.
The water-based invisible liquid can transfer onto anything it comes into contact with - including skin and clothing.
It is only visible under an ultra-violet light, meaning those who come into contact with it could be unaware that it has left a mark on them.
It stays on the skin for weeks and SmartWater scientists only require a speck of the solution to be able to forensically determine where it has a come from.
SmartWater is also extensively used to mark property, making it uniquely identifiable.