He and Morgan Mengel tried to poison her husband by spiking a juice drink with liquid nicotine, prosecutors said, and when that failed, he used company shovels to bludgeon his boss to death at the West Goshen Township firm.
Chief Deputy District Attorney Patrick Carmody, who was assisted at trial by Assistant District Attorney Deb Ryan, said in an interview Tuesday that "they texted as they were doing the murder . . . play by play," because she was not at the murder site.
"Her lover texted the message, 'It's done.' And she texted back, 'Pulse?' "
The Mengel and Shappell families were both troubled, investigators said.
Shappell's father, Harry F., died of a self-inflicted gunshot wound in October 2005 in the Newtown Square home where the boy lived with his parents and younger brother. The suicide followed years of financial and personal problems for the elder Shappell and his longtime girlfriend, a relative said in 2010.
The Mengels married in August 1998, seven months after the birth of their first child, but soon separated, court records show.
Three times during the next decade, they ended up in Family Court, but all three times the complaints were withdrawn.
The first murder trial in February 2012 ended in a mistrial after a police officer repeated, under questioning by a prosecutor, a comment by Morgan Mengel's father that his daughter "could be despicable."
In his 14-page opinion recommending a retrial, Gavin said the content of text messages between Morgan Mengel and Shappell "was devastating to the defense" and therefore concluded that the prosecutor had not attempted to sabotage the trial.
Contact Walter F. Naedele at 610-313-8134 or at firstname.lastname@example.org.