The gunman has been arrested and in custody after going to the office, asking for Gwatney and shooting him, Reports say three shots were fired.
"He came in and went into this office and started shooting," police Lt. Terry Hastings told reporters near the party headquarters.
Gwatney, a former legislator, was in critical condition, Hastings said.
The suspect was chased into Grant County, south of Little Rock, and apprehended after being shot, the police spokesman said. The suspect's condition was not known.
A witness said Gwatney's secretary ran into the flower shop she works at and asked to call 911. After asking for Gwatney and being told he could not see him, the gunmen barged into his office and shot the party chairman.
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