Based in Ballinascreen, Groogan became a sports coach with a particular involvement in hurling. He became prominent in his local Gaelic Athletic Association, and joined Sinn Féin. In 1991, Bernard O'Hagan, a Sinn Féin councillor for the Sperrin area of the Magherafelt District Council, was assassinated, and Groogan was appointed as his replacement.
Groogan held the Sperrin seat, heading the poll in each council election from 1993 to 2005. He became the first Sinn Féin Chairperson of Magherafelt District Council, and served a second term starting in 2004. He was elected to the Northern Ireland Forum in Mid Ulster, but he did not stand in the subsequent 1998 Northern Ireland Assembly election.
In 2006, Groogan resigned from Sinn Féin, along with Oliver Hughes, but continued to sit on the council as an independent. Hughes described their resignations as "purely a domestic issue", but the Sunday Times speculated that they may have been in protest at a lack of internal party democracy.
- "Groogan elected Chair of Magherafelt District Council", An Phoblacht, 17 June 2004
- Magherafelt District Council Elections 1993-2005, Northern Ireland Elections
- Newry and Armagh, Northern Ireland Elections
- Liam Clarke, "Key members quit Sinn Fein over controls", Sunday Times, 24 September 2006.
|Northern Ireland Forum|
|Member for Mid-Ulster
1996 - 1998