More letters Dellen Millard wrote to his girlfriend while in prison were read aloud Monday at his murder trial.

Millard and Mark Smich have both pleaded not guilty to first-degree murder in connection with the death of Hamilton resident Tim Bosma.

Bosma vanished on May 6, 2013, after taking two men for a test drive of a truck he had listed for sale.

Millard was arrested four days later.

On the witness stand Monday was Christina Noudga, who was dating Millard at the time of his arrest. It was her third day of testimony.

Last Thursday, jurors heard readings of several of the 51 letters Millard wrote Noudga while incarcerated.

In those letters, Millard claimed he had “helped clean up Mark’s mess” after Smich “f---ed up a truck robbery.”

He later turned his attention to preparing for his trial, writing at one point that he and Noudga “need to get our stories straight.”

Further thoughts in that vein seemed apparent in some of the letters detailed Monday.

In one, dated Oct. 19, 2013, Millard asked Noudga for her phone records for four days around the time of Bosma’s disappearance.

“Send me a copy and keep a copy for yourself, so that I can write you about them and we can cross reference,” he wrote.

Noudga testified that she could not recall if she had ever sent Millard the records he was asking for.

Eight days later, Millard wrote Noudga asking that she keep quiet about their communications, and asking him to be his “secret agent” in carrying messages between his various friends and acquaintances.

“We’re dealing with a ‘lay charges first, investigate later’ police force,” he wrote.

Another letter, dated Nov. 30, 2013, saw Millard musing that his phone records would likely be used against him at trial.

“I need evidence that indicates that I am not the only person that uses that phone,” he wrote.

“It’s most important to establish this on the night Bosma disappeared. I want supporting evidence … that it was usual/normal for me to lend my phone to Mark.”

Noudga said she never acted on Millard’s requests to relay messages to other witnesses.

Jurors heard that several of Millard’s letters were sent with instructions that they should be destroyed after they were read.

During this period, Millard and Noudga were subject to a court order barring them from communicating with each other.

In the spring of 2014, Noudga was charged with being an accessory to murder after the fact.

The trial continues Tuesday, with cross-examination of Noudga expected.