BOSTON — It was an odd moment in the trial of a friend of the man accused of carrying out the Boston Marathon bombing: Michael Dukakis, the former Massachusetts governor and 1988 Democratic presidential nominee, testifying for the defense.

Dukakis took the stand in federal court Thursday for Robel Phillipos, a friend of bombing suspect Dzhokhar Tsarnaev, to tell jurors about a conversation he had with Phillipos five days after the deadly bombing.

Phillipos, 20, is charged with lying to authorities about his movements three days after the April 15, 2013, attack that killed three people and injured more than 260.

Dukakis described himself as a longtime family friend of Phillipos and his mother. He said his wife, Kitty Dukakis, had worked as a social worker with Phillipos’ mother, and the two families remained friends.

Dukakis said Phillipos’ mother called him on April 20, 2013, and said she was worried because she hadn’t heard from her son for two days. Dukakis said he asked for Phillipos’ cellphone number, then called him.

“He told me he had been questioned for five hours by the FBI,” Dukakis said. “He told me he was so confused he didn’t know what he said.”

The spectacle of a well-known politician testifying at the trial was not lost on jurors, who listened attentively as Dukakis briefly described his political career and his conversation with Phillipos.

Dukakis, 80, said he first met Phillipos when the defendant was about 4 or 5 years old. He said Phillipos came to his home over the years and he took him to the Democratic National Convention in 2004, when Phillipos was 10.

“We’ve certainly watched him grow up,” Dukakis said.

Phillipos wiped away tears with a tissue as Dukakis described their long relationship.

Dukakis told reporters that during their conversation, he urged Phillipos to contact his mother. “I said, ”˜Well, call your mother, will you? She’s very concerned.’”

Prosecutors say Phillipos lied about being in Tsarnaev’s dorm room at the University of Massachusetts-Dartmouth when two other friends removed Tsarnaev’s backpack and other potential evidence just hours after the FBI released photos of Tsarnaev and his brother as suspects. At the time, an intense manhunt was underway to find the Tsarnaevs.

Dukakis’ testimony appeared to be designed to support the defense contention that Phillipos was a frightened and confused 19-year-old when he was questioned by the FBI and did not intentionally mislead investigators. The defense also says that Phillipos was so high on marijuana that he couldn’t clearly remember what he did the night of April 18, 2013, when the two other men removed

Tsarnaev’s backpack.

Under cross-examination by Assistant U.S. Attorney John Capin, Dukakis acknowledged that he has no personal knowledge about what Phillipos told the FBI when he was interviewed. Capin asked Dukakis if Phillipos had told him that he had lied to federal agents about what he saw happen in Tsarnaev’s dorm room, if he would have advised him to contact the FBI.

“If he had told me that, sure, but he didn’t,” Dukakis said.

Phillipos attended high school in Cambridge with Tsarnaev and later attended UMass-Dartmouth with him.

Prosecutors say he told a string of lies to the FBI during several interviews until he finally confessed to being in Tsarnaev’s dorm room and seeing the two friends take Tsarnaev’s backpack, which contained fireworks that had been emptied of their explosive powder. The backpack was later recovered in a landfill.

The other two men were convicted of conspiracy and obstruction of justice.

Dukakis told reporters he was comfortable testifying for Phillipos.

“All I know is … you’ve got testimony that’s relevant in the case ”“ I don’t care who the defendant is ”“ you’ve got the responsibility to … provide that testimony,” he said.

Dukakis had two stints as Massachusetts governor, from 1975 to 1979 and 1983 to 1991. He was the Democratic nominee for president in 1988, losing to Republican George H.W. Bush.