The directors of two burglar alarm businesses are facing possible jail sentences after being convicted of a sales scam.
A Leicester Crown Court jury found Dean Michael Mayes and Nadeena Campbell guilty of fraudulent trading and conspiracy to commit fraud by false representation.
They were also convicted of conspiracy to engage in unfair commercial practice.
During a six-week trial, the court heard how homeowners were persuaded into signing burglar alarm contracts, costing between £2,000 and £3,000.
Some customers were conned during "cold calls" into thinking they were being offered free alarms under a Government-backed crime awareness campaign.
Others were wrongly told there was a "special promotion" in their area.
To close a deal, sales staff would falsely claim only a few alarm units were left, which customers had to sign up for on the spot or lose out.
Mayes was director of Wilson Phillips (UK) Ltd, trading as Practical Security, and his then partner, Campbell, later took over as director of Practical Security Solutions Ltd.
The offences took place between April 2010 and June 2013.
One of their salesmen, Mark Sidney Durant, was also convicted of one count of engaging in unfair commercial practice, between May and June 2012, by using "undue influence" to sell an alarm system to a couple in their late 80s, who suffered from ill-health and already had a council-funded life-line alarm fitted.
The court heard they paid out £2,699 for a Practical Security alarm system they did not need.
Their daughter spotted the second alarm control box during a visit.
Her attempts to get the system removed were ignored.
Durant was acquitted of conspiring with Mayes and Campbell to commit fraud by false representation and conspiracy to engage in unfair commercial practice.
Judge Philip Head adjourned the case until September 25 for the preparation of pre-sentence reports.
Releasing all three on bail, he said: "These are serious matters and certainly for Mayes and Campbell it's likely to be a custodial sentence."
The defendants denied the charges, claiming they acted in good faith and had many satisfied customers.
The directors claimed sales canvassers had acted "off piste", going beyond official company instructions about what to say to prospective clients during cold calling.
John Hallissey, prosecuting, told the jury: "They preyed upon the fears and insecurities of homeowners."
Mr Hallissey said Mayes (37) and Campbell (34), who were both living at Browning Street, Narborough, jointly ran the companies.
Practical Security was based at Black Seam House, St John's, Enderby, from April 2010 until it ceased trading in May 2011.
Practical Security Solutions Ltd, based in Morris Road, Knighton Fields, Leicester, "arose from the ashes".
Durant (48), of Conalgen Road, Aylestone, Leicester, was a salesman who delivered sales pitches. Mr Hallissey said: "Customers were cold called out of the blue.
"They were misled to get a salesman into their house."
Mr Hallissey told the jury: "Practical Security was prepared to say whatever was necessary to sign people up for their alarms and take the money."
After the verdicts, Gary Connors, legal affairs manager for Leicestershire County Council trading standards, said: "The guilty verdicts are the culmination of an intensive and challenging investigation.
"A number of victims were also required to give evidence, some of whom were elderly, and we pay tribute to them for their resolve.
"Trading standards will continue to investigate rogue trading and, where appropriate, bring criminal proceedings against those who choose to trade unfairly and dishonestly."
