A Unity man is appealing his conviction for the first-degree murder of his girlfriend, claiming Westmoreland County prosecutors failed to adequately prove that a homicide was committed.

According to recently filed court documents, the lawyer for Thomas G. Stanko contends the guilty verdict imposed in February following a weeklong trial should be overturned and a new trial is warranted.

“The commonwealth did not prove beyond a reasonable doubt that the alleged victim is in fact deceased,” according to the appeal filed on Stanko’s behalf by defense lawyer Marc Daffner.

Stanko, 55, was convicted of the April 2018 murder of his girlfriend, Cassandra Gross, whose remains were never recovered. Prosecutors contended Stanko killed Gross, then 51, and discarded her body. Stanko maintained his innocence at trial and during a sentencing hearing earlier this month in which he was ordered to serve a life prison term without the possibility of parole.

Westmoreland County Common Pleas Judge Michael Stewart II also imposed a consecutive sentence of 42 to 84 months in prison for the arson charge, in which Stanko was found guilty of burning evidence and possibly Gross’ remains.

In the appeal, Daffner argued that prosecutors only offered speculative evidence as to where the murder allegedly took place and the manner in which Gross was killed. He contends jurors were improperly allowed to hear testimony from Stanko’s former wife about abuses he inflicted on her that were similar to allegations related to his treatment of Gross.

A series of witnesses testified Gross was at Stanko’s home shortly after she was last seen having lunch with a friend in Southwest Greensburg. Some of her belongings were found in burn pits on Stanko’s Unity property and nearby land owned by his mother.

Other witnesses testified they believed Stanko was abusive toward Gross.

Meanwhile, Gross’ burned-out SUV and her diabetic dog were found days after she was reported missing near the home of Stanko’s mother.

A Westmoreland County judge declared Gross legally dead in 2019.

“The entirety of the case … was based on unsubstantiated conjecture rather than fact, consists solely of circumstantial evidence and the conviction in this matter was based upon speculation that the petitioner ‘must have’ committed the crimes alleged …,” Daffner wrote in the appeal.

Stewart scheduled a hearing for June 19 to hear arguments pertaining to Stanko’s appeal.

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