David San Antonio died in 2004 of a rare genetic disorder that left him blind and wracked with tumors.

Those who knew him say that before he died, the 38-year-old Methuen, Mass., police officer accidentally checked the wrong box when filing for his city pension, leaving his widow and two children without benefits.

J. Michael Ruane was a Democratic state representative from Salem, Mass., for 30 years, much of it on the powerful House Ways and Means Committee. He never contributed to the state pension fund nor filled out retirement paperwork. But as he neared death, Ruane asked friends in the Legislature for a pension that would benefit his widow.

Both cases went before the Legislature last year. The Beacon Hill insider got a break but not the local police officer.

In the closing days of their session last July, lawmakers rushed through special legislation giving a pension worth $33,000 a year to Ruane’s widow, over Gov. Mitt Romney’s veto. For the second consecutive legislative session, it let the San Antonio bill lapse.

“They took care of Ruane but didn’t take care of this young person,” said Kenneth Henrick, a former Methuen city councilor who fought for the San Antonio family.

The contrast, critics say, is emblematic of the Massachusetts public pension system — open to abuse by lawmakers who exploit loopholes to benefit well-connected friends and special interest groups — and often themselves.

Deals cost billions

The special deals come at a cost to taxpayers. A Pioneer Institute study estimated the price tag for loopholes in the law at $125 million last year — on top of the more than $1 billion taxpayers paid into the system to make up for shortfalls.

Kenneth Ardon, author of the study and a Salem State College economist, estimates $3 billion of the state’s roughly $14.5 billion unfunded pension liability can be attributed to early retirement and other deals for those in favor with legislators, including members of powerful public employee unions.

The “Retirement Plus” plan alone cost $1.2 billion, he said. Billed as a way to older, higher paid teachers to retire early, it also enhanced the pensions of teachers statewide.

“It means a chunk of money in the future that could have been used for something else goes to pensions,” he said.

Ardon said the system has been so skewed there is no clear relation between what employees pay into it and what they ultimately receive. Some state employees actually get less than the value of their investment, while others get far more.

“There is a disconnect,” said Ardon. “What you put in doesn’t connect with what they pay out.”