An anonymous friend doubled the reward offering this week for information that leads police to the killers of two Sikh restaurateurs shot last month in a mysterious attack at their Richmond business.

Ravinder Kalsi, 30, and his brother, 42-year-old Paramjit Kalsi, died a few minutes after closing Sahib Indian Restaurant the night of Dec. 27. Two men walked up to the door, knocked to attract Ravinder's attention and began shooting when he opened the door.

"The surveillance camera footage of the suspects (released last week) has generated a lot of calls and tips," Richmond police Detective Sgt. Mitch Peixoto said. "But so far, nothing has panned out."

The brothers ran the restaurant for five years, originally a sideline to their work renovating and selling residential properties. Police say they planned to sell the restaurant, but so far they can deduce no motive from the family finances.

Local police also have enlisted aid from FBI hate-crime investigators to probe the possibility of that motive.

The Kalsis lived together, raising money to send home to family in Punjab. Ravinder soon planned to marry in India, friends said.

The Richmond Police Department offered a $10,000 reward for information leading to the arrest and conviction of their killers. The anonymous benefactor offers an additional $10,000, said Gurman Bal, a friend and former roommate.

A brother of the Kalsis arrived Monday from India to help facilitate transportation of the bodies, Bal added.

Police ask anyone with information about the Dec. 27 killings of Ravinder and Paramjit Kalsi at Sahib Indian Restaurant to call Detective Nicole Abetkov at 510-412-2087 or call the anonymous tip line at 510-232-TIPS.

Reach Karl Fischer at 510-262-2728 or kfischer@bayareanewsgroup.com. [Link]