CHICAGO - A man with Philadelphia ties accused of helping to plan the attacks in Mumbai, India, that left 166 dead is to appear in court today to respond to the charges, federal prosecutors said.

David Coleman Headley, 49, now of Chicago, is due to appear before U.S. District Judge Harry Leinenweber for arraignment.

Headley was charged Monday with scouting locations in Mumbai that later became the targets of bloody attacks in November 2008 blamed on members of the Pakistan-based group Lashkar-e-Taiba.

The group, whose name means Army of the Pure, is an outgrowth of decades of friction between Pakistan and India over the disputed territory of Kashmir. Lashkar-e-Taiba has been outlawed in Pakistan and designated by the United States as a foreign terrorist organization.

Headley's father, Syed Saleem Gilani, was Pakistani and his mother the Philadelphia socialite and pub owner Serrill Headley. The two divorced and both have died.

Headley and Rana met as teenagers at a prestigious Pakistani boarding school before his mother brought him back to the United States.

He was arrested in Chicago in October and charged initially with plotting to attack the Jyllands Posten newspaper in Denmark that had published 12 cartoons depicting the Prophet Muhammad in 2005, setting off protests in the Muslim world.

Unlike his codefendant in that case, Chicago businessman Tahawwur Rana, 48, Headley, who changed his name from Daood Gilani, has not yet appeared in court.

Rana's attorney, Patrick Blegen, has been attempting to get his client freed on bond. He says Rana appears to be an honest businessman who was duped by Headley.

Headley could be sentenced to death if convicted of the charges involving the attacks in Mumbai.

His attorney, John T. Theis, said he would "continue to look at this and see what the evidence is," but declined to comment further.

A Virginia woman whose husband and 13-year-old daughter were killed in the Mumbai attacks said in a statement Monday she was grateful U.S. authorities had charged Headley.

"My hope is that Headley cooperates fully and discloses all information to aid in the investigation," said Kia Scherr, whose husband, Alan, had gone to Mumbai to find a location for a meditation retreat.

A retired major in the Pakistani military, identified as Abdur Rehman Hashim Syed, also was charged Monday with conspiring to attack the Danish newspaper and its employees, according to U.S. court documents.

Pakistan has said it has a retired major in custody for questioning over alleged links to Headley and Rana, but officials yesterday gave no details about where he was being held or what Pakistani charges he might face.

An FBI team arrived in India on Monday and will also visit Pakistan.

"Both our countries are working closely together to share information on the Headley-Rana case and working to detect and prevent future threats," the U.S. ambassador to India, Timothy J. Roemer said in a statement.

The U.S. charges indicate Headley apparently was in Pakistan as late as January to contact Ilyas Kashmiri, who has been linked to al-Qaeda and described as a leader of the extremist group Harakat-ul Jihad Islami.

Pakistan's role in alleged plots spanning three countries has come under scrutiny as details emerge about the case and Headley's links to the country.

The country's security agencies have a long history of supporting Lashkar-e-Taiba and other groups as proxies against archrival India in the disputed region of Kashmir.

Islamabad says it no longer backs such groups, but many powerful Pakistani politicians and army officers are believed to remain sympathetic to the cause, raising concerns they could be potential recruits for more global Islamist extremists like al-Qaeda.