The news that Mark Kerrigan, brother of the former Olympic ice skater Nancy Kerrigan, may have played a role in his father's death was shocking. But that revelation was followed closely by another: that in March 2008, Daniel and Brenda Kerrigan had taken the unusual and difficult step of suing Mark -- suing their own son -- for allegedly refusing to pay back more than $100,000 in loans.
86-year-old Peg Savo of Clarks Summit, Pa., knows just how difficult it is for a parent to decide to sue a child. She is in the middle of a lawsuit against her only son, Frank.
"I am brokenhearted. I can't sleep some nights thinking about it. Mother's Day is coming…I didn't see him Christmas or Thanksgiving and it's been like this for two years," she said.
For years, Peg and her late husband Frank were involved in the real estate business in Clarks Summit, aquiring a number of properties in both of their names. When Frank Savo died he left everything to his wife.
But after his death, Peg Savo's health went downhill for a time -- she had a hip replacement, felt depressed and was on medication.
At that time, according to Savo's attorney, Ernest Preate Jr., 54-year-old Frank J. Savo asked his mother to sign some documents -- which she only later realized gave him control over her financial affairs and sole ownership of her real estate holdings.
They are currently valued at more than a million dollars. Calls by ABC News to Frank J. Savo were not returned.
Peg Savo's attorney says in August 2009, after a year's worth of phone calls and fruitless discussions, she filed suit against her son and two of his business partners.
"He came to me with something to sign so I signed it, but I couldn't believe it when I found out later what he did," she said.
"I was shocked. I trusted him implicitly with everything. Why would an only son do this to his mother?"
The case of Mark Kerrigan is similarly tangled. According to court documents obtained by the Boston Herald, Daniel and Brenda Kerrigan claimed their son owed them money they had paid to cover many of his living expenses over several years. The list included $31,870 in mortgage payments, $1,336 for heating oil and $197 for cat food.
Mark Kerrigan, said the suit, never paid his parents back. At the time of lawsuit he was serving a two-year jail sentence on various charges including assault. Kerrigan also had a long history of run-ins with the law involving substance abuse.
In his 23 years as an attorney in Charleston, S.C., Lyndsey Blanks has handled several cases in which a parent sued a child.
"It's so horrific that you remember it when it happens," he told ABC News.
Blanks said when a parent makes the decision to take legal action, in his experience, it is "always a last resort," and invariably involves an allegation of financial impropriety.
Blanks remembers one case in which a mother sued her daughter to recover $80,000 -- a life's worth of savings -- that was removed from a joint checking account.
"People don't think their children will treat them that way," said Blanks, who added that his hardest job is often convincing parents to not sign over a power of attorney to their children without thinking through the consequences.
A power of attorney allows a child decision-making power and control of a parent's assets.