The Chester County woman accused of persuading her young lover to help kill her husband recently told the man that she gave birth to his twins in prison and needed to be released so she could raise them, prosecutors said.

The fabrication - she had not given birth - highlights the lengths to which Morgan Marie Mengel, 35, will go to avoid responsibility for the death of Kevin E. Mengel Jr. on June 17, 2010, according to a pretrial motion filed Thursday by First Assistant District Attorney Patrick Carmody and Assistant District Attorney Deborah Ryan.

Authorities said Mengel and Stephen M. Shappell, 22, an employee of Kevin Mengel's landscaping business, MKB Property Maintenance, spiked the victim's lemon Snapple with nicotine, after which Shappell fatally bludgeoned him with a shovel and buried the body behind Marple Newtown High School, which Shappell had attended.

Prosecutors want to introduce the correspondence Morgan Mengel had with Shappell in prison, where both are awaiting trial on homicide charges, as well as evidence that Mengel had been trying to make her husband "vanish" for at least two years.

By "playing on [Shappell's] sympathy," the motion says, the letters "document her continued attempt at manipulating him to achieve her goals in minimizing her role in the murder."

Evidence of prior "bad acts" is admissible only if it shows a pattern or motive and is not outweighed by its prejudicial effect, according to state law.

"There's certainly a basis for the commonwealth's position," said lawyer Thomas J. Wagner, who represents Shappell. He declined to elaborate.

John J. McMahon Jr., Mengel's attorney, did not return a telephone call or e-mail.

The petition says Mengel, who had a history of infidelities, tried to kill her husband in 2008 by putting sleeping pills into a drink but they only rendered him unconscious. It says multiple witnesses will testify that she expressed hatred for her spouse and said divorce was not an option because she did not want a custody fight over the couple's three children.

In prison letters to Shappell and conversations with another inmate, Mengel suggested writing a book that would "make millions and scillions of money" and running away to "our own island," the petition says.

She described her labor and delivery of twin boys to Shappell and produced "a birthing announcement which names and describes the babies," the petition said.

A pretrial hearing before Chester County Judge Thomas G. Gavin is scheduled for Wednesday.

According to court records, the Mengels, who married in 1998 after the birth of their first child, were embroiled in custody disputes dating to 1999.

Contact staff writer Kathleen Brady Shea at 610-696-3815,, or @brandywinebits on Twitter. Read her blog, "Chester County Inbox," at