Seventy-six-year-old Shirley Thomas trusted the man who called her Mom and went to the store with her to buy materials for renovating her two-bedroom Makiki apartment.

The man signed a contract with Thomas in August 2012 to replace her cabinets, countertops, bathroom tiles, wallpaper and floor tiles. He also promised to repaint her walls and redo her electricity and plumbing, all for $12,375.

Nearly two years later, Alexander Nebre, doing business as Al’s Construction, has abandoned the work. He left the kitchen countertop covered with a plywood board, the floorboards installed in the wrong direction and the hallway marked up with a shoddy paint job, Thomas said at her home recently.

Thomas said she gave Nebre more than $60,000 from her retirement savings for materials until he stopped coming about four months later. These days she can barely afford to buy groceries, and her debt has swelled to more than $90,000 from credit card and cash advance interest fees, she said. She thinks she may have to move to the mainland to survive.

And the floorboards Nebre never installed still sit on her lanai.

"I’m just so frustrated," Thomas said Sunday. "I’m so beaten down."

Nebre could not be reached for comment.

Police say Nebre is notorious for posing as a licensed contractor to scam his victims. He currently has three criminal cases against him involving a handful of victims, and detectives are looking into at least two other cases, police said.

Authorities say he is one example of an ongoing problem involving unlicensed and uninsured contractors.

Nebre was charged last month with second-degree theft and unlicensed-contractor fraud for allegedly taking more than $5,000 from an elderly Kai­muki couple from March 27 to April 3. He was released after posting $150,000 bond.

Nebre allegedly committed that crime while out on bond for another case of unlicensed contracting.

In February, Nebre was charged with second-degree theft for allegedly stealing money by deception from a woman in 2011. He was released after posting $40,000 bond.

Police said the crime involved Nebre posing as a licensed contractor.

And then on April 4, Nebre was charged with six counts of second-degree theft involving four victims in 2012.

In that case Nebre allegedly received nearly $10,000 from a man through deception, $6,800 from another man for labor charges, $19,600 from a woman for labor and home repair materials, and $14,277 from the fourth victim for work he didn’t finish, according to court records.

Nebre pleaded not guilty in April and was released after posting $75,000 bond.

Daria Loy-Goto of the state Regulated Industries Complaints Office urged residents to contact her agency to verify contractors are licensed before hiring them and to never pay with cash.

She said state authorities are concerned about people like Nebre who aren’t stopped by civil fines.

"The challenge is really we want to stop the conduct, and sometimes getting fines is not going to be enough," Loy-Goto said. "That’s why we are fortunate to be able to work with criminal law enforcement."

Loy-Goto said her office has opened 47 cases in the past five years involving unlicensed contractors targeting seniors.

"It’s a persistent and continuing problem," she said.

In June 2013 a state judge ordered Nebre to pay $88,980 in fines and $204,566 in restitution to four victims, according to court records.

Those records detailed Nebre’s alleged offenses:

» In March 2010, Nebre offered to make repairs to a 70-year-old woman’s house for $17,550. After being paid, Nebre abandoned the project.

» In July 2010 an 89-year-old woman paid Nebre $10,900 for home repairs, then withdrew an additional $35,550 in cash for Nebre after he requested it.

» In February 2011, Nebre said he would do repairs for an 87-year-old woman for $75,919. He collected the money and left the job unfinished.

» Also in 2011, Nebre offered to do repairs for a 90-year-old woman for $42,600 and also borrowed $20,000. He never finished the work and never repaid the loan.

In all four cases Nebre acted as a contractor but wasn’t licensed, the documents said. He never repaid the victims, even after the court ruling.

Loy-Goto said the state is strengthening laws to crack down on unlicensed contractors. In April, Gov. Neil Abercrombie signed a law increasing the fine for unlicensed contractors who commit crimes against victims older than 64 to $20,000 from $10,000.

Loy-Goto said the state also has a law that upgrades a third conviction for unlicensed contractor fraud to a felony from a misdemeanor.

Loy-Goto said complaints from victims are still important because they alert the state to other possible offenders.