A doctor from Sands Point, who faces up to 25 years in prison for his alleged involvement in a murder-for-hire scheme in which he planned to kill a rival cardiologist earlier this year, was arraigned Monday in Nassau County Court.

Dr. Anthony Moschetto, 54, was first under investigation by U.S. Drug Enforcement Administration agents for selling Oxycodone pills out of his office in Great Neck, but the investigation escalated into a case involving arson, the sale of drugs and assault weapons, a murder plot and a room filled with weapons that was hidden by a moving bookshelf inside the doctor's million-dollar home, Nassau County District Attorney's office said. Moschetto, who was arrested April 14, pleaded not guilty to the following grand jury 77-count indictment charges:

First degree criminal possession of a weapon

Four counts of third degree criminal possession of a controlled substance

Four counts of third degree criminal sale of a controlled substance

Second degree conspiracy

Third degree arson

39 counts of criminal sale of a prescription for a controlled substance

Four counts of third degree criminal sale of a firearm

Third degree burglary

Second degree criminal mischief

Two counts of second degree criminal solicitation

Fourth degree conspiracy

14 counts of fourth degree criminal possession of a weapon

Two counts of fourth degree criminal solicitation Bail was continued at $2 million bond or $1.25 million cash. "The defendant was a respected member of the community, caring for patients in Nassau County, but allegedly he had a sinister side and ordered the death of a rival cardiologist," Acting Nassau County District Attorney Madeline Singas said in a statement. "Working with our partners in the NCPD and DEA, we were able to break up this complex murder-for-hire plot before someone was killed."

Undercover detectives bought drugs from Moschetto's seller on six different occasions from Dec. 2014 to March of this year. The Oxycodone pill investigation led to the additional undercover purchases of heroin and two fully loaded assault weapons, police said. An undercover detective also learned about the seller's pursuit of dynamite to blow up a property believed to be the office building of a rival doctor, police said. At a press conference in April, Acting Nassau County Police Department Commissioner Thomas Krumpter called Moschetto a "hidden monster living in the North Shore area who has no respect for law and life."

The dispute between Moschetto and his fellow doctor happened several months ago, police said. The two doctors worked in the same office building, located at 38 Northern Boulevard in Great Neck. After the dispute, Moschetto moved his offices to a different location in Great Neck.

Authorities did not name the fellow doctor, but last year the website of Heart Diagnostic Imaging listed Moschetto as the partner of Dr. Martin H. Handler. The cached version of the website says Moschetto joined Handler in the practice in 1994.

Authorities believe the business dispute is what caused Moschetto to hire two men, James Chmela, 44, of Selden, and Jack Kalamaras, 41, of Suffolk County, to commit arson to the competing cardiologist's practice around Feb. 22. Moschetto first planned to purchase dynamite to blow up the doctor's office, but he decided to have the office set on fire instead, police said. Authorities were able to quickly extinguish the fire, which damaged the office but caused no injuries.