Islamabad, Pakistan ? Two new reports on the assassination last month of Pakistani opposition leader Benazir Bhutto suggest that the killing may have been an ambitious plot rather than an isolated act of violence and that the government of President Pervez Musharraf knows far more than it’s admitted about the murder.

A police officer who witnessed the assassination said that a mysterious crowd stopped Bhutto’s car that day, moving her to emerge through the sunroof. And a document has surfaced in the Pakistani news media that contradicts the government’s version of her death and contains details on the pistol and the suicide bomb used in the murder.

The witness was Ishtiaq Hussain Shah of the Rawalpindi police. As Bhutto’s car headed onto Rawalpindi’s Liaquat Road after an election rally Dec. 27, a crowd appeared from nowhere and stopped the motorcade, shouting slogans of her Pakistan Peoples Party and waving party banners, according to his account.

Bhutto, apparently thinking she was greeting her supporters, emerged through the sunroof of the bulletproof car to wave.

It was Shah’s job to clear the way for the motorcade. But 10 feet from where he was standing, a man in the crowd wearing a jacket and sunglasses raised his arm and shot at the former prime minister. “I jumped to overpower him,” the deputy police superintendent said later. “A mighty explosion took place soon afterwards.”

Shah suffered multiple injuries and is recuperating in a Rawalpindi military hospital, guarded by agents of Pakistan’s Inter-Services Intelligence directorate.

Who organized the crowd is only one of the mysteries two weeks after the assassination. “I don’t know who they were or from where they came,” the Rawalpindi officer told Dawn newspaper. “They just appeared on the road.”

The second report emerged in the Pakistani media, with detailed information about the pistol and bomb. It rejects the government’s conclusion that Bhutto died when the force of the suicide blast threw her head against the sunroof lever of her car. Such an impact couldn’t have fractured her skull, it said.

The government refused to confirm the report’s authenticity, but a security official verified it to McClatchy. He spoke only on condition of anonymity because of the sensitivity of the subject.

According to the report, a pistol made by Norinco, a Chinese brand, was recovered from the scene, with the lot number 311-90. An MUV-2 triggering mechanism for the bomb also was found, as had been used in 15 previous suicide bombings in Pakistan, with the same lot number and factory code.

“It is a clear indicator that the same terrorist group is involved in almost all these incidents,” concluded the report, which was quoted at length in the Pakistani daily newspaper The News.

Another mystery of the case is why so valuable a report has been buried. Among its other conclusions: Bhutto’s assassin, after shooting her, detonated his own suicide belt. No ambulance was called, and it took 25 minutes to get her to the hospital, only two miles from the scene.