A lawyer working for an oil-equipment company shot to death a fellow attorney while the two were sitting at a desk Thursday morning, then killed himself, police said.

The victim, shot in the head, was a patent lawyer with Cooper Cameron (search) oil services. The men's names were not immediately released. Police said they were in their 50s or 60s.

Capt. Dwayne Ready (search) said police had no immediate clues as to a motive.

Two handguns — a .357 caliber revolver and a semiautomatic — were found beneath the chair of the gunman, who was working under contract at Cooper Cameron, which makes pressure-control systems for oil drilling.

The shooting happened on the fifth floor of the Cameron building in west Houston.

About 700 people work in the nine-story building, and normal operations had resumed by midmorning everywhere but on the fifth floor, which remained closed. Police were interviewing the 50 employees who were on the floor when the shooting occurred.

"There are a whole lot of people who are walking around kind of stunned," Ready said.

The building had no metal detectors, but Ready said homicide detectives were reviewing tapes from the building's security cameras.

Cooper Cameron said it would provide counselors to employees. President, chairman and chief executive Sheldon R. Erikson (search) said officials were "deeply saddened by the tragic events."

"Our thoughts and prayers are with their families, friends and co-workers at this difficult time," he said in a statement.