So the story was that Brian Terry was killed in a 'chance encounter';

then it may have been cartel killers looking for Border Patrol people; now, something else comes to light:
Sources now tell PJ Media that neither version of events is accurate: the rip crew was not waiting for a chance encounter with other illegals, nor did the members intend to engage American law enforcement agents.

The rip crew was in Peck Canyon that evening with the intention of stealing money and drugs from a specific shipment of which they had prior knowledge.

Sources claim the Department of Justice has been trying for almost a year to hide the key information — how the rip crew knew the shipment was coming through that night.
...
The rip crew knew to be in Peck Canyon that December evening because a CI working for the FBI found out about a smuggling run — from the FBI.

It is not clear if the information was provided intentionally, but a possible motivation for the FBI to provide the information is known to exist: the CI had previously lost a shipment of drugs, and wanted to regain the trust of the cartel with an offering of drugs or money. The other possibility is that the FBI mistakenly allowed the CI to discover the information.

The CI used this information to organize an ambush of the drug convoy. A source tells PJM that the FBI knew from wiretaps that the CI was using their information to set up an ambush.

The Drug Enforcement Administration (DEA) — through its own CIs and communications intercepts — was also aware of the planned assault.

Neither the DEA nor FBI warned Border Patrol about the expected criminal activity.
And isn't THAT just a fucking wonderful thing to find out? Gets even more thrilling:
...The existence of a third recovered gun, an SKS carbine, has been disputed by the FBI despite the fact it had been talked about openly in the beginning of the investigation among federal agents.

Multiple sources tell PJM that this third weapon “disappeared” because it was the weapon carried by the FBI CI who ran the rip crew. When it was recovered near the scene of the murder and subsequently traced by the ATF, it traced back to the FBI CI via the gun shop in Texas where it was purchased.
Not Phoenix, not even Arizona: TEXAS.
In this case, the FBI and DEA failed to deconflict. Neither agency bothered to warn Border Patrol to keep their BORTAC teams out of Peck Canyon that evening. As a direct result of this FBI and DEA failure — combined with Homeland Security forcing BORTAC units to carry less-lethal beanbag rounds in some of their primary weapons — Brian Terry’s under-armed four-man unit walked into an ambush against a heavily armed rip crew, at least five of whom were carrying rifles.

Brian Terry’s murder was entirely preventable. The incompetence of the DEA and FBI let his Border Patrol unit walk into an ambush. After the ambush, it appears the FBI tampered with evidence to cover up that one of their informants was involved with the murder of a federal agent.
God damn these people. They KNEW. And bloody Holder and Napolitano and Mueller and Obama ALL KNEW. And some of them have lied under oath about it, and continue to lie. And literally God only knows how many people are dead because of their plans.