[8] Lawlor was sent to South Vietnam in November 1971, and by the beginning of 1972 was working in counterintelligence in the Danang regional headquarters.

[9][10][11][12][13] In 1974 Lawlor received a direct commission in the United States Navy Reserve as an intelligence officer.

[21] In addition, he attended the National Security Fellows Program at Harvard University's John F. Kennedy School of Government.

[24][25] In this assignment Lawlor oversaw creation of the Civil Support Team concept, an initiative that enables the National Guard to play a greater role in responding to domestic terrorism than has historically been allowed since the passage of the Posse Comitatus Act.

[30] When DHS was officially founded in March, 2003 Lawlor was named its first Chief of Staff, and he served until being succeeded by J. Duncan Campbell in October, 2003.

[31][32][33] In 2003 Lawlor earned a Doctor of Science degree in engineering management from George Washington University.

[34] Since leaving DHS Lawlor has continued his involvement in national security affairs through both academia and private business, including: member of the board of advisors for the Global Panel Foundation; member of the Homeland Security Advisory Council (HSAC); chief executive officer of Centuria Corporation; distinguished service professor at the Stevens Institute of Technology; professor at the George Washington University; instructor at the Army War College; and director of the Center for Technology, Security, and Public Policy at Virginia Polytechnic Institute and State University (Virginia Tech); advisory board member for Patron Systems, Inc.; and chairman and chief executive officer of Community Research Associates, Inc.[35][36][37][38] After leaving Virginia Tech, Lawlor was a senior associate at the Center for International and European Studies.