Greg Meffert, the chief technology officer and key adviser to former Mayor Ray Nagin, told jurors in Nagin’s corruption trial Friday afternoon that the mayor was well aware that City Hall technology vendor Mark St. Pierre was the benefactor behind Nagin family trips to Hawaii and Jamaica, cell-phone service for the Nagin sons and landscaping services at the mayor’s home.

That testimony was more or less expected, and it helped to build the government’s case that Nagin was knowingly accepting cash and things of value from city contractors. Asked how he know that the mayor knew the source of the first-class tickets to Jamaica, which cost roughly $6,000, Meffert said: “Because we talked about NetMethods (a St. Pierre firm) and Mark, and I wanted to make sure Mark got credit for it.”

Meffert’s account of a trip to Chicago and Las Vegas, on which Nagin first met businessmen Aaron Bennett and Frank Fradella, was also potentially damning. In Meffert’s telling, Bennett offered his help in getting work for the Nagin family granite firm, Stone Age, in exchange for the promise of city work, and Nagin was extremely solicitous.

But the most surprisingly evidence and testimony of the day involved a series of “pin-to-pin” communications between Meffert and the mayor – essentially text messages – that Meffert said were sent that way in order to avoid detection.

“Emails, because it was a public record, we pretty much stayed on pin for anything that was sensitive,” Meffert testified. He said that federal authorities recovered the messages directly from the phones.

The meaning of the messages highlighted by prosecutors is sure to be hotly debated. In several of them, Nagin and Meffert are talking about the mayor’s conversations with Bennett about a possible business relationship.

In one email message, Bennett wrote to the mayor, saying: “Frank asked Scott (Sewell) and I to visit with you regarding the structure of the relationship between HSOA (Home Solutions of America) and your family granite business. Are you avail for a cup of coffee tomorrow morning?”

Later, Nagin wrote back: “Nope. Not interested. My sons will not be able to do business with you guys as long as you go after city business.”

The exchange will almost certainly be touted by the defense of evidence of Nagin’s innocence. But Meffert suggested that the mayor was nervous because Bennett was being indiscreet by sending a message that could be easily obtained through a public records request – and that the mayor’s response was intended to be discovered if that happened.

In a pin-to-pin message to Meffert, the mayor seemed to be openly discussing doing business with Fradella, but he suggested that using his son as a liaison would either make it legal or provide cover.

“I must tell you I am not comfortable with the way this is going down,” Nagin wrote. “Talked to Frank today and advised him it would be the best if his folks worked thru Jeremy so we could keep the city out of this partnership.”