A Howard County jury has convicted Richard Baumgardner of kidnaping a 29-year-old woman at knifepoint from a Columbia office building on Jan. 4, two days before he allegedly raped a Montgomery County woman and threw her from the Rocky Gorge Bridge into the Patuxent River.

The Howard County woman, testifying this week at a trial before Circuit Court Judge Robert Fischer, pointed to Baumgardner as the man who forced her into her car about 4:45 p.m. She told the court that as Baumgardner drove her 1983 red Datsun down Rte. 29, she pretended to have a heart attack. Then, she testified, with her body blocking his view, she unlocked the door on the passenger side of the car and when he slowed for a red light, she jumped out and ran for help.

At the trial, which ended Tuesday with Baumgardner's conviction, the woman identified a brass key ring found in his blue truck as one belonging to her. The key ring was marked with an "M," the initial of her first name.

Assistant State's Attorney Gerry Hogan, who prosecuted the case, said Baumgardner faces up to 50 years in prison for the kidnaping and armed robbery. Sentencing is set for July 22.

This is Baumgardner's second major conviction. He was convicted in 1976 of raping a Howard County woman and served six years.

On Jan. 6, two days after the Howard County woman was kidnaped, a 30-year-old woman getting into her car in the Wheaton Plaza Shopping Center was kidnaped, raped and then thrown into the Patuxent River, which runs between Howard and Montgomery counties. The woman swam to shore and flagged down a motorist, who contacted police.

Montgomery County authorities charged Baumgardner with attempted murder, rape and robbery after finding his truck in the shopping center next to the spot where the victim's car had been parked. She identified him from a photograph as her assailant, police said.

Baumgardner is scheduled to be tried Aug. 28 in Montgomery County.