The Israeli police said Sunday that they had arrested a 37-year-old American immigrant, a West Bank settler, and charged him in an array of killings and terrorist attacks over the last 12 years, including the murders of two Palestinians, the bombing of a leftist Israeli professor’s home and the maiming of a 15-year-old boy who belongs to a community of Jews who believe in Jesus.

The suspect, Jack Teitel, a father of four and a computer technician and Web site designer, was born in Florida, the son of a military dentist. He went back and forth between Israel and the United States starting in the 1990s, immigrating here in 2000. His parents followed a year later and live in a different West Bank settlement.

The murders with which he has been charged, of a taxi driver in Jerusalem and a shepherd south of the West Bank city of Hebron, took place in 1997. The attacks on the teenager and on the professor occurred last year.

Mr. Teitel is also charged with having attacked police officers on several occasions.

“This investigation has exposed a dark and dangerous world where human life was lost and people were injured against a background of ideological extremism,” said Dudi Cohen, Israel’s police commissioner. He said it had involved extensive cooperation between the police and the Shin Bet internal security force. The arrest occurred several weeks ago but was subject to a court blackout until Sunday.

Mr. Teitel, who goes by the Hebrew name Yaakov, lives with his wife, Rivka, and four young children in Shvut Rachel, a central West Bank settlement. He asserted that he acted alone in all cases, the police report stated.

In recent years, Mr. Teitel seemed especially agitated over gay Jews, the police said. He put up posters against gay rights and attacked a police station in 2006 in hopes of diverting officers from protecting a gay pride parade. At a briefing for reporters, the police said he confessed to two killings at a gay community center in Tel Aviv in August, an event that shook the nation. But the police concluded that he had not been involved in it.

The officers said they found weapons, ammunition and a weapons laboratory in his house. They also said he had smuggled weapons from the United States when he immigrated.

The Jerusalem professor whose house was pipe-bombed, Zeev Sternhell, is a vocal critic of the settlers and the political right in Israel. Professor Sternhell, a professor emeritus of political science at Hebrew University of Jerusalem, was lightly wounded.

Reacting to the arrest, Professor Sternhell said that Sunday was an important day in Israeli democracy and that he hoped Mr. Teitel would be treated no differently from any other terrorist suspect, meaning Palestinians charged with such activity.

The Israeli boy who was badly injured a year and a half ago, Ami Ortiz, is still recovering from wounds caused by an explosive placed in a gift basket traditionally given out on the Jewish holiday of Purim. His mother, Leah Ortiz, also American and living in the West Bank settlement of Ariel, said in a statement that her “blood ran cold” when she heard about the arrest, especially the knowledge that the suspect lived only minutes away.

“We are horrified by the fact that there are elements of Israeli society, Jews who feel justified in taking the lives of other Jews because of their beliefs,” she added.

The Ortizes are part of a small and mistrusted community of messianic Jews in Israel, who consider themselves Jewish but believe in Jesus.

Mr. Teitel’s neighbors said they were amazed and found it hard to believe that he committed the crimes he was accused of. Some described him as a loner but others called him quite sociable.

“I have always known him to be a nice guy, someone who gave me rides, with a sweet wife,” said Batya Medad, a longtime resident of the nearby settlement of Shiloh. She recalled when Mr. Teitel arrived in the area as a bachelor and later found a wife and set up a home. “I was floored when I heard this.”

Mr. Teitel told the police that the murders were in response to Palestinian terrorist attacks.

He was detained in 2000 for those murders but freed because of insufficient evidence. It was only after the Sternhell bombing that the police began to note similarities in many of the attacks and picked up his trail again.