Freitekh, 28, was with a flight instructor in a twin-engine Piper PA-34 Seneca when the plane slammed into a utility pole.
According to two federal officials familiar with the probe, they do not believe he was affiliated with militant groups.
Feras Freitekh, 28, was with a flight instructor in a twin-engine Piper PA-34 Seneca when the plane slammed into a utility pole on Tuesday and burst into flames in East Hartford. Freitekh died in the crash and the instructor was badly injured.
The U.S. National Transportation Safety Board said on Wednesday that its initial investigation indicated the crash was "the result of an intentional act," and the FBI joined the probe.
Investigators came to believe that the crash was a suicide attempt by Freitekh after speaking with the instructor, said the two officials, who spoke on condition of anonymity.
There is no evidence Freitekh shouted religious statements before the crash and nothing else pointing to terrorism, the officials said. Freitekh had not been known to U.S. intelligence agencies.
East Hartford Police Lieutenant Joshua Litwin said at a news conference on Wednesday that he did not know who was flying the plane at the time of the crash. The aircraft had two sets of controls, allowing either person to pilot the plane.
Freitekh and the instructor, Arian Prevalla, argued and fought for control before the crash, the Hartford Courant reported on Wednesday, citing unidentified sources.
East Hartford police and the FBI field office in Connecticut could not immediately be reached for comment on Thursday.
The crash occurred across the street from the headquarters of aerospace manufacturer Pratt & Whitney, a unit of United Technologies Corp. Investigators looked into whether the manufacturer was possibly targeted.
Investigators, however, believe the plane was on the final approach to a small airport in East Hartford and had been cleared by air traffic controllers to land, one of the federal officials said.
Freitekh became certified last year as a private pilot for single-engine planes, according to Federal Aviation Administration records.