BELFAST, Maine — The man being held on $100,000 bail after allegedly planting several homemade explosives at the home of a Waldo County Sheriff’s Office detective earlier this month had help — and may have been motivated by the detective’s arrest of his older sister earlier that day.

Jesse Newton, 24, of Waldo, also is believed to have placed many more chemical explosive devices in front of Detective Merl Reed’s home on the evening of Jan. 4 than the three that had previously been reported, according to a press release issued Wednesday from the sheriff’s office.

“It was determined that someone had placed a large amount of nails in Detective Reed’s driveway and had placed nine or ten explosive devices in front of the residence, several of which exploded,” the press release stated.

Reed was home at the time of the attack and heard the explosions, which he reported to the Waldo County Communications Center. Police officials from both the Belfast Police Department and the Waldo County Sheriff’s Office responded to the incident.

On Tuesday, an official from the Maine State Fire Marshal’s Office said that three chemical explosives had been found on the property.

Reed was home at the time of the alleged attack, said Waldo County Deputy District Attorney Eric Walker, who did not know if any family members also were at the residence. No one was injured.

Newton was arrested on Jan. 5 and charged with criminal use of explosives, aggravated possession of marijuana and violation of a protection order. Details about the violation of protection order was not immediately available Wednesday.

Another man, James Hill, 23, of Searsport, was arrested Jan. 13 and charged with criminal use of explosives in connection with the same case.

According to Walker, Reed had arrested Newton’s 28-year-old sister, Juice Newton, earlier on Jan. 4 on a warrant for outstanding charges. Those included two counts of theft, one of forgery, two counts of violation of bail conditions, a Waldo County Jail official said. She was released on bail on Jan. 7 and has a Waldo County District Court date set for Feb. 14.

“Obviously, we think that is the motive,” Walker said Wednesday.

Both Newton siblings have past drug-related convictions, according to BDN archives.

In 2007, Juice Newton was arrested as part of a monthlong undercover investigation into a major cocaine trafficking ring that operated in Waldo and Kennebec counties. Juice Newton was found guilty in 2008 of Class B unlawful trafficking in scheduled drugs and was sentenced to spend three years in prison with all but 60 days suspended. She also was sentenced to two years of probation.

BDN archives show that Jesse Newton has two convictions on charges of marijuana cultivation in the last few years, as well as a 2010 conviction on a charge of harassment.

Walker argued to a judge after Jesse Newton’s latest arrest that his bail should be set higher than usual because of his prior record and because he is a “risk to the integrity of the judicial process.”

The fact that Newton targeted an officer’s home gave rise to the sense that he is a risk to the process, Walker said. The crime left local police officials on edge.

“We don’t see crimes like this very often. It’s pretty rare,” the deputy district attorney said.

Efforts Wednesday to contact Newton’s defense attorney, Steven Peterson of Rockport, were unsuccessful.

Jesse Newton is being held at Two Bridges Regional Jail in Wiscasset. His bail was set at $100,000 surety or $15,000 cash.

Hill was released on Jan. 13, after posting $1,000 cash bail. His Waldo County Superior Court date is set for March 29.