HARRISBURG — At least three men recently paroled from Pennsylvania prisons have been arrested in unrelated homicides over the past two months, leading to calls from prosecutors and prison guards for a review of the parole practices.

The men were arrested within a couple days of one another this month, all in cases with connections to domestic violence.

One is a convicted murderer who got out of prison in March and is now charged with killing an 8-year-old boy two weeks ago in the western Pennsylvania city of New Castle.

Two other parolees released from prison in the past two years are facing charges in the beating death of a 2-year-old Baltimore boy and the strangulation of a 49-year-old Hershey woman.

“I think the nature of the cases and the cluster is certainly what is alarming,” Jennifer Storm, the state’s victim advocate, said Monday. “When you’re talking about domestic violence and children, these are especially horrific and heinous crimes.”

The arrests come as the state has worked to lower the state’s prison population, in part by limiting the length of a prison stay for parole violators and providing parolees with more services in the community, such as skills training, mental health counseling and substance abuse treatment.

In recent years, the ranks of state parolees grew by a fourth, to 32,000, as parole violators spent less time in prison and more on the streets.

The Pennsylvania District Attorneys Association said it was troubled by the cases, and it urged a review.

“We should all expect that there will be an exhaustive review — by an outside entity if necessary — of each case in order to determine what, if anything, went wrong and what reforms can be implemented going forward to help prevent additional tragedies,” Lindsay Vaughan, the organization’s executive director, said in a statement.