The Boston Police Department reports that Anthony Davis, 37, will be arraigned on a murder charge for his role in an April gun battle on Mattapan Street that left his grandmother, Eleanor Maloney, 74, dead, shot in the head.

The man charged with firing the bullet that killed Maloney, Dane Henry, 23, of Roxbury, will have his earlier manslaughter charge increased to murder, police say.

At Henry's arraignment on manslaughter charges, a Suffolk County prosecutor said Maloney was standing on the sidewalk outside her Mattapan Street home around 5 p.m. on April 6 when Henry and Malone began firing at each other. Each fired eight rounds, prosecutors say.

Both shooters were injured, Davis, seriously enough that he was initially arraigned in a hospital bed on various gun charges.

Even if Davis did not fire the bullet that killed his grandmother, he can be charged with murder on a legal principle known as joint venture, on the theory that he knowingly participated in a criminal action that led to her death.

According to police, Davis will be arraigned in Suffolk Superior Court on Monday on charges of murder, assault and battery by means of a dangerous weapon, unlawful possession of a firearm, fourth and subsequent offense, and being a Level 2 armed career criminal and habitual offender.