U.S. Border Patrol agents conducted an 11-hour vehicle checkpoint on Interstate 95 in eastern Maine on Wednesday, stopping southbound vehicles near Lincoln in Penobscot County to ask drivers and passengers for their citizenship and immigration status, and to search vehicles with sniffer dogs.

Agents from the Houlton Border Patrol sector manned the checkpoint, arresting a man from Haiti and seizing drugs. Border Patrol said it didn’t keep track of how many vehicles the agents stopped.

Civil rights groups have sharply criticized the practice of snap immigration inspections on highways and bus stations, and said some of the checks are unconstitutional.

The American Civil Liberties Union suspects inspections have become more common during the Trump administration, and in May it sued the U.S. government for records related to immigration enforcement efforts.

“We should all be able to live our lives without being stopped by immigration agents every time we board a bus or drive down the highway,” said Emma Bond, a staff attorney with the American Civil Liberties Union of Maine. “Having (Border Patrol) constantly intruding on our lives and demanding that we show our papers doesn’t make us any safer, but it will make us less free.”

Border Patrol would not name the man it arrested Wednesday, but said he was a Haitian national with an outstanding deportation order from 2007 and prior arrests for cocaine possession, possession of a concealed firearm and resisting an officer, as well as a protection order from Lee County, Florida. An immigration violation was issued to another person during the checkpoint, Customs and Border Protection spokesman Steve Sapp said.

Agents made nine narcotics seizures including some LSD, a case that was turned over to Maine State Police, he said.

Sapp said he did not know how many highway checkpoints Border Patrol has conducted in Maine in the last two years.

“The timing, locations and frequency of Houlton Border Patrol Sector’s tactical immigration checkpoints are law enforcement sensitive, and obviously due to operational security, checkpoint details are not something that we would publicly disclose,” he said in an email.

In an interview, Sapp said checkpoints are sometimes a tactical decision based on intelligence or a routine practice to check a route that may be used for smuggling. I-95 is a major artery on the East Coast, he said.

Border Patrol has the authority to conduct checkpoints within 100 miles of the nation’s land and coastal borders, which includes the entire state of Maine. Roughly two out of three Americans live within the 100-mile border zone, the ACLU said.

The checkpoint in Lincoln was at least the third on a New England highway in the last month, according to a review of Border Patrol statements.

Agents arrested 17 people on immigration charges and seized drugs and drug paraphernalia including marijuana products during a three-day operation on I-93 near Woodstock, New Hampshire, in late May.

Five more people were arrested for immigration violations and more marijuana products were seized during another three-day operation in the same part of New Hampshire last week.

Border Patrol planned to conduct five highway checkpoints in New Hampshire after Memorial Day, according to emails obtained by the New Hampshire ACLU.

In May, a New Hampshire court ruled that the arrests of 16 people on minor drug charges at a Border Patrol checkpoint in 2017 were unconstitutional.

Border Patrol also has conducted multiple immigration checks at a Concord Coach Lines bus stop in Bangor, including one in late May that was caught on camera. In an interview this week, Concord Coach Lines Vice President Ben Blunt said the frequency of Border Patrol checks has ramped up considerably in the last six months.

Checkpoints are designed to be “non-intrusive,” Sapp said. Border Patrol agents may look inside windows and use dogs to detect concealed humans or drugs. Agents need probable cause to conduct a legal search under the Fourth Amendment, Sapp said.

Border Patrol checkpoints do not give Border Patrol agents carte blanche to automatically search persons and inside vehicles,” he said.

Travelers have the right to remain silent if agents ask them about their citizenship or immigration status, but travelers who cooperate “are passed through quickly” unless an agent suspects a violation of federal law, he said.

People who refuse to cooperate may be referred to a secondary examination area for more questioning and can be charged with impeding law enforcement if they refuse to submit to a secondary examination, Sapp said.

U.S. Border Patrol agents operate an immigration checkpoint Thursday on Interstate 95 in Penobscot (Photo courtesy of U.S. Customs and Border Protection via PPH)