A 29-year old Seat Pleasant woman was abducted on her way to work yesterday morning and was bound, gagged and left in a cold, vacant apartment building for hours in a kidnaping that involved a demand for about $20,000 in ransom.

A suspect was arrested about 5 p.m. yesterday after a man allegedly approached the victim's stepfather at a designated ransom pickup point and asked for money.

The victim was found above five hours later in a building at 6610 Greg St. off the George Palmer Highway in Seat Pleasant. She was taken to a county hospital for observation. Police declined to provide her name.

The kidnaping prompted an intensive search and investigation, involving dozens of Prince George's county police officers, including some with dogs.

According to preliminary accounts the victim was leaving her car about 7:30 a.m. to enter the office where she is a private secretary when a man forced her back into her car and drove to the Greg Street apartment house.

Shotly afterward a caller telephoned the victim's parents, said she had been kidnapped and demanded ransom. The stepfather, owner of a concrete company, negotiated the demand down to the $20,000 figure and called police.

Police said Edwin W. Harrison, 27, of Fairmont Heights was arrested in a parking lot of a school near Addison Road and charged with kidnaping.