Two final court dates have been set for mid-April in the negligent homicide trial of James F. Lomma, the owner of the Kodiak tower crane whose fatal collapse killed two workers in Manhattan nearly four years ago. For more than a month, the owner of the equipment rental firm has been the focus of charges that say he was responsible for the 2008 deaths of union crane operator Donald Leo and sewer worker Ramadan Kurtaj.

With the prosecution resting its case, Lomma's attorneys began calling as witnesses in late March two crane forensic engineering experts employed by Haag Engineering. The defense has argued that forensic evidence shows the way the crane collapsed contradicts prosecutors' theories of the case. According to its website, the Irving, Texas, firm operates a "state-of-the-art research/testing laboratory that specializes in materials testing."

The website lists the first scheduled Haag witness, principal engineer Jim D. Wiethorn, as having "crane accident analysis" as a key consulting area. The second scheduled defense witness, engineering specialist Edward P. Cox, is an expert in the evaluation of mechanical and structural failure of mobile equipment and weld and component failures. He is set to appear on April 9. Prosecutors say they will offer a rebuttal, with closing arguments from both sides possibly set to begin as early as April 16.

Prosecutors claim that Lomma, the former owner of New York Cranes and J.L. Cranes, encouraged his former mechanic Tibor Varganyi to a buy replacement turntable for one of his defective cranes from an "unknown" Chinese company called RTR to save time and money on repairs, although RTR's track record in such work was not verified.

Varganyi pleaded guilty last October to identical charges of criminally negligent homicide in the accident. As part of his plea, he agreed to testify against Lomma, whose two firms are also defendants. Manhattan Assistant District Attorney Eli Cherkasky claimed that Lomma hired Varganyi for a job usually held by a licensed engineer, although Varganyi had only a ninth-grade education. On the witness stand, the 65-year-old admitted he lacked the basic math skills to measure the parts, say published reports.

The New York Post ridiculed another witness against Lomma, former regulator Michael Carbone, dubbing him "Inspector Clouseau" for admitting to cursory examination of the turntable. Prosecutors characterized him as compromised by his former employment with Lomma.

High-profile negligent homicide cases recently tried in New York City against industry officials after other fatal accidents have proved difficult to prosecute, as demonstrated by the 2010 acquittal of a crane rigger in a separate 2008 crane collapse as well as three project supervisors last year in a fatal 2007 high-rise fire.

At least one union source believes the case may end similarly and notes that Lomma's firms, which may still be operating under other management, nearly have a monopoly on tower-crane rentals in the New York City area. But Bernadetta Panzella, who represents Leo's survivors in civil litigation, believes Lomma will not escape conviction. Manhattan Criminal Court Judge Daniel Conviser is set to rule without a jury on Lomma's fate.