The Minuteman Project, a volunteer border-patrol group, says it is pressing Columbia for an investigation into the melee that occurred on October 4, when three Minutemen were assaulted on campus as they tried to deliver speeches.

One Minuteman, Marvin Stewart, filed a complaint on October 10 for stolen property with the Lake Forest Police Department in Orange County, Calif., according to an office technician at the police department, Mary Ann Zimmerman.

Mr. Stewart filed another complaint with the New York Police Department on October 11 for harassment, according to Detective Kevin Czartoryski of the NYPD. The latter complaint, filed with the NYPD’s 26th precinct in Morningside Heights, details the way in which Mr. Stewart was harassed as he delivered a speech before the audience of Columbia students.

A spokesman for the Minuteman Project, Tim Bueler, said the founder of the Minuteman Project, Jim Gilchrist, will file a complaint this week with the NYPD charging Columbia students with assault and stolen property. “His glasses were taken and the podium was pushed into him,” Mr. Bueler said.

The third Minuteman at the Columbia event, Jerome Corsi, said he would not file a police report but said he planned to take part in a potential lawsuit. Mr. Bueler said that an Orange County lawyer, Jack Robbins, is preparing the Minutemen’s case.

Mr. Bueler said that Messrs. Stewart, Gilchrist, and Corsi sent a letter yesterday to Columbia University demanding a comprehensive investigation into the events of October 4. Mr. Bueler said that the Minutemen had not been contacted by Columbia since the event, nor had they received an apology, and that without a thorough investigation and a demonstration of remorse by the university, the Minutemen would proceed with their lawsuit against the school.

“We’ll wait to give Columbia some time to respond and then go from there,” Mr. Bueler said.

But Mr. Corsi said he was ready for a legal showdown. “Columbia University is partially federally funded and civil rights violations undoubtedly took place that night,” Mr. Corsi said. “We’ll be looking at civil rights statutes in order to file a federal case.”

Mr. Corsi said that he had planned to read from “Minutemen: The Battle to Security America’s Borders” (World Ahead), the book he co-authored with Mr. Gilchrist, but was prevented from speaking when the event broke up. “Those are two primary examples of free speech, writing a book and reading from it,” Mr. Corsi said. “I felt like it was a denial of free speech when I was unable to read from my book.”

A Columbia University spokesman did not return phone calls seeking comment. The president of Columbia, Lee Bollinger, has called the melee deplorable, has said the university is investigating, and has warned the students involved that they may face disciplinary action.