Lawyers for Boston Marathon bombing suspect Dzhokhar Tsarnaev have persuaded a federal judge to grant them access to prison documents and photos of their client, apparently to help them build a case mitigating against the death penalty.

Additionally, District of Massachusetts Magistrate Judge Marianne Bowler on Tuesday granted a joint motion to delay Tsarnaev’s probable cause hearing until July 2. She approved his sealed evidentiary motions late last week and on Monday.

Bowler denied Tsarnaev’s request that his defense counsel be allowed to take "current and periodic photographs of the defendant," but said that they could be present when prison staff takes his photo. Tsarnaev argued that his "injuries over time" would be evidence of "his evolving mental and physical state" and reveal "the voluntariness of [his] statements and sentence mitigation arguments," she wrote.

Tsarnaev, 19, is accused of planting two bombs with his brother Tamerlan near the marathon’s finish line on April 15. Tamerlan Tsarnaev, 26, was fatally wounded during an April 19 early morning shootout with police. The bombs killed three people and injured more than 260. The brothers also allegedly killed a Massachusetts Institute of Technology police officer while on the run.

Tsarnaev was charged with one count of using and conspiring to use a weapon of mass destruction resulting in death and one count of malicious destruction of property by means of an explosive device resulting in death. If found guilty, he could face the death penalty, although the U.S. Department of Justice has not said whether it would seek his execution.

On Monday, Bowler ordered the U.S. Bureau of Prisons to comply with Tsarnaev’s attorneys’ written requests to see his daily activity logs, suicide watch logs, psychological files, photographs, commissary file and any central file. She denied their request to stop the bureau from giving the files to the government without defense counsel’s consent and a court order.

Regarding the photos, Bowler cited security rules related to cameras at Federal Medical Center Devens in Ayer, Mass., where Tsarnaev is being held. Those rules bar visitors—including pretrial detainees’ lawyers—from using cameras.

"Refusing to allow the defendant’s counsel to bring a camera and take photographs or refusing a request to require BOP staff to use a memory card provided by the defendant’s counsel is reasonable in light of legitimate security concerns," she wrote.

She continued: "To accommodate the defendant’s request, however, BOP staff at FMC Devens will allow its staff to take pictures of the defendant at the facility with the defendant’s counsel present. This reasonable accommodation adequately addresses the defendant’s need to document the defendant’s condition."

Federal public defender for the District of Massachusetts Miriam Conrad declined to comment. She and two assistants, Timothy Watkins and William Fick, are defending Tsarnaev with Judy Clarke of San Diego’s Clarke & Rice. Clark, selected for her expertise in death cases, did not respond to requests for comment. The Boston U.S. Attorney’s Office also declined to comment.

"Certainly getting access to these things is, I’m sure, significant to some of the issues that [the defense team is] dealing with," said David Hoose of Sasson Turnbull Ryan & Hoose in Northampton, Mass. He is handling a capital case in Rhode Island but isn’t involved in the Tsarnaev matter.

Hoose said Tsarnaev’s physical appearance over time and recorded information about him would help defense lawyers during the penalty phase of his trial.

"It’s going to be a starting point for mitigation," Hoose said.

Sheri Qualters can be contacted at squalters@alm.com.