BOSTON — An FBI informant has described his correspondence with a Massachusetts man accused of participating in a plot to behead a conservative blogger who angered Muslims when she organized a Prophet Muhammad cartoon contest in Texas.

Using the alias Yusuf Ali, the informant testified Tuesday in Boston federal court that he and David Wright communicated online for about 18 months.

Ali said he didn’t initially think Wright, who had “actually rejected the Boston bombings,” was a threat. But Wright became more radicalized over time.

Prosecutors allege the 28-year-old Wright, his uncle and another man agreed to kill Pamela Geller in 2015. The plot wasn’t carried out.

Wright’s attorney has portrayed him as a lost young man who became consumed by the Islamic State group in attempt to escape reality.