It’s been over three months since the awful story about Steve McNair’s murder first broke, and from virtually the first moment on, all the convenional wisdom has suggested that his illicit girlfriend, Sahel (or “Jenny“) Kazemi had killed McNair before turning the gun on herself.

CBS NEWS, however, seems to think otherwise - or at the very least, seems to think the police’s investigation was a combination of incomplete and inaccurate. And while some questions they raise are a little less convincing than others, the totality of the CBS investigation certainly makes the circumstances of the incident seem a little less plausible than before.

[UPDATE: CBS’s Arman Keteyian says his investigation has prompted “a major breakthrough” in the case. No details, of course.]

For the first part of CBS’s report, released today, click here to watch on CBS.COM. Or if you prefer, the highlights:

• According to employee records, Kazemi was not absent from work for two hours the day police say she bought a gun; that was the day prior, before her DUI arrest;
• According to jail surveillance tapes, Kazemi was not visibly upset after her DUI;
• According to friends, Kazemi was still acting in normal spirits up until the day of the shooting;
• According to bank records, Kazemi was not in dire financial straits; she was up to date on her bills and had over $2,500 in her bank account when she died.

All of this seems to contradict the police’s report, which states that Kazemi had “spiraled out of control” in the days leading up to the shooting. CBS says they have more information coming tomorrow.

Unfortunately, all of this evidence is circumstantial; it doesn’t explain why McNair died of four bullet wounds but Kazemi only one; it doesn’t take the murder weapon out of her hand; it doesn’t put anybody else in the place of death; most importantly, it doesn’t provide new evidence about a different killer.

We’ll wait for more information tomorrow from CBS - they say they’ve got something about the relationship between Kazemi and the man who allegedly sold her the gun - but we’re skeptical that anything’s going to change from the police’s point of view unless CBS introduces an actual alternative theory.