Mengel's wife, Morgan Mengel, 34, was charged by West Goshen police with her husband's homicide on Friday. It was believed to have taken place June 17 at the business they owned, MKB Property Maintenance in West Chester.
Shappell, an employee of the business, is then alleged to have buried Kevin Mengel's body behind his old high school in Delaware County. The whole bizarre, Bermuda-like love triangle is summed up by Shappell's favorite quote, as listed on his Facebook page: "WOW, WOW, WOW, WAIT A MINUTE, WAIT A MINUTE!"
Police began their investigation on June 20 - Father's Day - when Kevin Mengel, 33, the father of three, was reported missing by his mother, Kathleen Barton. Barton, who was too distraught to speak yesterday, became concerned when she began to receive uncharacteristic text messages from her son's phone and see unusual postings on his Facebook page, police said.
"As the investigation went on, it became more and more obvious something happened to him," West Goshen Police Sgt. Michael P. Carroll said yesterday.
At first, Morgan Mengel claimed her husband of 11 years had left her, but after Shappell showed up at her apartment while she was being interviewed by a detective, she admitted to having an affair, according to the The Daily Local News of Chester County, which obtained the arrest affidavit.
The next day, when the two showed up at the landscaping business together while a detective was there, Shappell allegedly fled in Morgan Mengel's truck when she took the investigator inside.
Police said that Morgan Mengel tried to kill her husband by putting something in her husband's drink but when that failed, Shappell hit him over the head with a shovel on June 17 at the business.
It was a business Morgan and Kevin Mengel had built "from the ground up with help from family & friends," they wrote on the company's Facebook page.
For reasons yet unknown, Shappell then took the body to his alma mater, Marple-Newtown High School, in Delaware County, where he buried it behind the school. It was found by search dogs and investigators on Saturday, police said.
Ironically, the slaying took place four days before another alleged love-triangle murder in which a jealous spouse is accused of killing an Army veteran in a Springfield, Delaware County, parking lot.
Just barely old enough to drink and already suspected of murder, Shappell, of Marple Township, said he likes to "have a good time and get the most outta life," on his Facebook profile.
"I think music is one of the best things in the world it can cheer you up, calm you down, or just get you psyched about anything," he wrote. Now, he'll have to face the music.
The Associated Press contributed to this report.