Shappell was an employee of Kevin Mengel's landscaping business, MKB Property Maintenance, and was having an affair with Morgan Mengel, police said. His last known address was in Broomall.
Kevin Mengel was killed at his West Goshen Township business June 17, West Goshen Police Chief Michael J. Carroll said.
A coroner's preliminary report determined that the death was a homicide and that Mengel had suffered blunt trauma, Carroll said. A final determination of the cause of death will not be made until toxicology results are received.
Kevin Mengel's mother reported her son missing last Sunday after she received a suspicious text message purporting to be from him. Investigators later determined that Morgan Mengel had sent the message to cover up the slaying, Carroll said.
Morgan Mengel at first said that her husband - the father of their three children - had left and did not want to be bothered. The evidence pointed in a different direction, Carroll said.
Saturday, hours after Morgan Mengel's arrest, police, assisted by cadaver dogs, unearthed Kevin Mengel's body.
Carroll applauded the work of the many departments involved in the case, including Newtown Township police, Westtown-East Goshen police, detectives from Chester and Delaware Counties, and the Malvern-based Search and Rescue Dogs of Pennsylvania.
"Investigators took a routine report of a guy's disappearance . . . delved into it and quickly determined that something was suspicious," he said. "Within a week, we have one person locked up and were able to find the body; that's pretty good police work."
The Mengels married in 1998 and were embroiled in custody disputes dating to 1999, according to court records. Morgan Mengel filed for divorce in 2004 but withdrew the complaint about a month later.
Shappell was last seen in Morgan Mengel's white, 2001 Ford Quad short-bed pickup truck with Pennsylvania license plate YSB-9330. Anyone with information on his whereabouts is asked to call West Goshen police at 610-696-7400.
Contact staff writer Kathleen Brady Shea at 610-696-3815 or firstname.lastname@example.org.