BANGOR, Maine — The Hermon man who in February fired shots that mortally wounded a Bangor man and injured his friend during a reported home invasion was arrested Thursday for drug trafficking and possession of synthetic bath salts.

“He was arrested on a sealed [Penobscot County grand jury] indictment,” Deputy Chief Troy Morton of the Penobscot County Sheriff’s Office said Friday. “It was a sealed warrant.”

Daniel Williams, 25, was arrested on several sealed warrants, the most serious being felony aggravated drug trafficking, which could send him to prison for up to 30 years, the deputy chief said.

The drug trafficking charge is “the result of an investigation which was started Feb. 16, 2012,” Morton said. “This investigation is ongoing.”

Feb. 16 is the day Williams used a .22-caliber handgun to fatally shoot Robert Dellairo, 30, of Bangor and wound Philip McIntyre, 19, also of Bangor in the leg during a reported home invasion, he told the Bangor Daily News shortly afterward.

Williams’ bail conditions bar him from having contact with McIntyre and others who were at the scene or in the getaway car.

“Williams posted bail on May 31 in the amount of $5,000 cash and is scheduled to appear at the Penobscot Judicial Center on July 19 for his arraignment,” Morton said.

The sealed warrant for Williams’ arrest also charges him with unlawful possession of scheduled drugs, unlawful possession of hallucinogenic drugs and criminal forfeiture of property.

Williams told the Bangor Daily News that he was asleep at his residence at the Duran Apartments on Outer Hammond Street when Dellairo and McIntyre broke into his residence.

“They attacked me in my home, and I had to protect myself,” Williams said just days after the incident.

Williams said he used a .22-caliber handgun to shoot Dellairo in the pelvis, McIntyre in the leg and shot twice into the rear end of a blue Honda Accord that a woman used to drive the injured to St. Joseph Hospital.

Dellairo was immediately transferred from St. Joseph Hospital to Eastern Maine Medical Center, where he later died. McIntyre was arrested for burglary after he was released from St. Joseph and was booked into the Penobscot County Jail. Since then, he has been arrested at least two other times.

The two women involved, one of whom reportedly knocked on Williams’ door, and Luis Ramos, who was with Williams at the residence, have not been charged.

Williams and Ramos initially told police they did not know the people who broke into their residence, Penobscot County Sheriff’s Office Sgt. Mike Burgess said shortly after the shooting.

Dellairo’s father, who is also named Robert Dellairo, said recently that “they all knew each other.” The elder Dellairo told the Bangor Daily News in May, “My son was no angel,” but said he didn’t deserve to die over a drug deal gone bad.

The younger Dellairo, who is survived by a young child, and the group he ran with knew Williams and he was into the drug “monkey dust,” the street name for synthetic bath salts, his father said.

“When you get a lot of drug dealers together they all lie through their teeth,” said the elder Dellairo, who lives out of state but returned to Maine to deal with his son’s death.