An appeal trial is set to begin for a Bridgeport gangster serving life in prison for the 1984 killing of a teenager who worked for him. Thomas Marra Jr. was convicted in the early 1990s of murdering 15-year-old Alex Palmieri, who vanished after he started talking to investigators about Marra. Police said Palmieri was beaten and stuffed into a refrigerator that was dumped in Long Island Sound. Two years later in 1986, police said a sneaker with part of Palmieri’s foot in it washed ashore in Bridgeport and became key evidence at Marra’s trial. Marra’s habeas corpus appeal trial is set to begin Tuesday at Rockville Superior Court. The Connecticut Post reported that Marra claimed he did not get a fair trial and is challenging tape-recorded evidence against him.