BURLINGTON, Vt. — A Los Angeles biotech investor pleaded not guilty Tuesday in a transcontinental murder-for-hire conspiracy that led to the 2018 abduction and killing of a Vermont man.

Serhat Gumrukcu, a 39-year-old Turkish citizen, appeared in U.S. District Court in Burlington, where he entered the plea to a charge of interstate murder for hire during a brief hearing before Judge Geoffrey Crawford. If convicted, he could go to prison for life.

A Vermont State Trooper, center, speaks to a homeowner, Thursday, Jan. 8, 2018, near an area on Peacham Road, in Barnet, Vt., where the body of Gregory Davis was found. Los Angeles biotech investor Serhat Gumrukcu pleaded not guilty Tuesday, Oct. 4, 2022, in a transcontinental murder-for-hire conspiracy that led to the 2018 abduction and killing of Gregory Davis. Dana Gray/Caledonian-Record via AP, file

Gregory Davis, 49, was abducted from his home in Danville on the night of Jan. 6, 2018, by a man wearing a jacket with a U.S. Marshals Service insignia and carrying a rifle and handcuffs. Davis’ body was found the next day in a snowbank on the side of the road about 15 miles away, in the town of Barnet.

Davis’ wife, Melissa Davis, declined to comment after the hearing. Gumrukcu’s husband, William Anderson Wittekind, of Los Angeles, also declined to comment.

Investigators identified the alleged kidnapper – Jerry Banks, of Fort Collins, Colorado – to a cellphone that was used to make a 911 call made about 15 minutes before the kidnapping in which the caller claimed to have killed his wife at a nonexistent address. Investigators traced the phone that Banks used to make the call to a Walmart in Pennsylvania where Banks bought it while on his way to Vermont.

Initially, Banks was only charged with kidnapping Davis, and even though prosecutors alleged that he killed Davis, he wasn’t charged with the killing. But on Tuesday, prosecutors announced the charges against him had been amended and that he is facing the same murder-for-hire charge as Gumrukcu and Berk Eratay, who worked for Gumrukcu. Banks’ attorney did not immediately respond to a message seeking comment.

Investigators subsequently linked Banks to Aron Lee Ethridge, of Las Vegas, who hired him; to Eratay and then to Gumrukcu.

Banks previously pleaded not guilty to the initial charge, but he hasn’t entered a plea to the murder charge announced Tuesday. Eratay has pleaded not guilty. Ethridge pleaded guilty over the summer, and attorneys are going to recommend a sentence of 27 years in prison.

Prosecutors allege that Gumrukcu, 39, was involved in an oil deal with Gregory Davis. After Gumrukcu missed payments, Davis threatened to report him to law enforcement.

In 2017, Gumrukcu was putting together a different deal through which he obtained a significant ownership stake in Enochian Biosciences, of Los Angeles. Prosecutors have said that any complaints by Davis to law enforcement could have ended the Enochian deal.

After Gumrukcu’s arrest, Enochian issued a statement saying there was no link between the company and the crime with which Gumrukcu is charged.

Last week, during a separate hearing in Rutland in the Eratay case, Assistant U.S. Attorney Paul Van de Graaf told Crawford that if the three defendants go to trial, officials expect to try them together.

Eratay and Banks also face sentences of life in prison if convicted.