Massachusetts authorities have issued an arrest warrant for 33-year-old Aaron Pennington of Gardner in connection with the shooting death of his wife, 30-year-old Breanne Pennington. The warrant was issued on Wednesday by Gardner District Court, as investigators found a disturbing note in Aaron Pennington's cellphone that provided probable cause for his involvement in the crime, according to Worcester County District Attorney Joseph Early Jr.

On Tuesday, a search warrant was issued to search specific content on Aaron Pennington's cellphone. While reviewing a limited portion of the phone's content, investigators came across a note dated 7:04 p.m. Saturday, which read, "Don't say anything. Be quite [sic] If she wakes up just say you're getting nasal spray. Get on side of bed - very close proximity to head. Put hole in her head." This note led authorities to believe that Aaron Pennington was responsible for his wife's murder.

Close acquaintances of the Pennington couple revealed that Aaron had been struggling with mental health issues and had previously made threats of suicide. It was also known that the couple had been experiencing marital problems, and Breanne Pennington had made plans to leave with their four children.

Since Sunday morning, when Breanne Pennington was found dead inside their home on Cherry Street, Aaron Pennington has remained at large. Authorities are cautioning the public not to approach him, as he is considered armed and dangerous. An Air Force veteran, Aaron Pennington's whereabouts are currently unknown.

The investigation began on Sunday when Gardner police received a 911 call from a concerned neighbor. The neighbor reported that the Pennington children had arrived at her house, stating that they couldn't find their father and their mother was crying in her bedroom. First responders arrived at the Cherry Street residence and discovered Breanne Pennington lying in bed with a gunshot wound to the head. She was pronounced dead by a paramedic shortly after.

A sweep of the house was conducted by the police, but no one else was found inside, and no visible weapons were discovered, apart from the firearm that Breanne Pennington had for her protection. During the execution of a search warrant, investigators did not locate the firearm, but they did find three spent shell casings in the bedroom where Breanne was found.

An autopsy conducted on Monday determined that Breanne Pennington's death was a result of gunshot wounds to the head, ruling her death as a homicide.

Video surveillance obtained from a neighbor showed Aaron Pennington leaving the driveway of their Cherry Street home at around 8:50 a.m. on Sunday. The footage also captured the Pennington children leaving the house and seeking help from the neighbor. On Monday, a hunter discovered Aaron Pennington's white 2013 BMW 320 sedan approximately 1,500 feet down a wooded trail near Camp Collier in Gardner.

Despite an extensive search carried out by local and state police, Aaron Pennington has yet to be apprehended. The wooded area of approximately 200 acres near the Ashburnham town line has been scoured, but no widespread search is planned for Thursday unless new information emerges.

The investigation into Breanne Pennington's death and the search for Aaron Pennington continue to be conducted by the Gardner Police Department, Massachusetts State Police, and state police detectives assigned to the Worcester County District Attorney's Office. Anyone with information regarding Aaron Pennington's whereabouts is urged to contact the authorities at 911, Gardner police at 978-632-5600, or state police at 508-829-8326.

As the search intensifies for Aaron Pennington, the community remains on high alert, hoping for a swift resolution to this tragic incident.