[UPDATED Dec. 9, 2010, 7:16 AM, Pacific Time. Headline changed to more accurately reflect staus of case]

Beverly Hills Police investigating the shooting death of Hollywood publicist Ronni Chasen now say they believe the gun ex-convict Harold Smith used to kill himself last week is the same weapon used to kill Chasen, TMZ reports.

Investigators say they think Smith acted alone and killed Chasen in a robbery attempt, according to the report. The attempted robbery, they say, was committed by a man riding a bicycle.

The latest information reverses theories that surfaced after Smith shot himself when he was confronted by police. After the suicide, reports circulated that Smith’s gun was not a match with the one used to kill Chasen.

Police got a break when a tip from the show “America’s Most Wanted” led them to Smith, who had reportedly been bragging to neighbors that he had shot Chasen for $10,000. Authorities say they do not believe Smith was working for anyone when he allegedly killed Chasen.